Long-term relationships are normally looked down onto not only by this subreddit, but also by a lot of guys that are somehow involved in Pick Up. I have been against long-term relationships too for a very long time. Although I will probably receive a lot of hate for it, I believe that there are mainly two reasons why people (especially on here) don't like the thought of having a long-term relationship:

  1. They already had at least one long-term relationship in the past and they fucked it up due to their own behavior. Now, not only did they develop an antipathy against long-term relationships, but also against women in general, which is why they will tell you stuff like "Never settle down with a woman, it's a trap! Women are evil, never trust them, they are going to betray you anyway!"

  2. They never had a long-term relationship in the past and didn't have sex in general until they were in their twenties, which is why they feel the need to overcompensate for that. "I was a virgin until I was 23 years old, now I fucked my first few girls, I can't settle down, I need to make up for all those years of sex with different women that I missed in the past!"

Let me be honest with you: I could have easily included myself in the second category not too long ago. I never had a girlfriend in my entire life until I was 23 years old, and I lost my virginity in the same year. I then fucked a few different women until I "finally" found my current girlfriend. We're together since almost a year now. Throughout the months where I started to approach women and finally had sex for the first time, I couldn't imagine getting a girlfriend. I thought that it was counterproductive for my personal progress, I thought that beginning a long-term relationship with a women is going to stop it entirely. Turns out that the opposite was the case actually. I can only tell you how having a long-term relationship for the first time helped me, I can't guarantee that it will help you in the same way, of course. Plus, regardless of what you may interpret, it is basically just a recommendation to not push against having a possible long-term relationship if you never had one like I did. I'm not saying "Go settle down with the first women you meet!", because if you don't love and desire her, there is obviously no point in doing so. Futhermore, if you already had a long-term relationship and are done with this concept for any reason whatsoever, this post is probably not going to help you anyway. It is written for people who would also include themselves in the second category from above. My goal is to show those kind of people that having a long-term relationship could be the totally right thing to do in order to gain a lot of personal progress. Here is my random list of benefits that I found for myself:

  1. Let's be real here: the reason why many of us in their twenties (or earlier) never had a girlfriend or sex in general is due to us being anti-social, weird, not having a lot of friends, poor self-esteem or not being able to communicate like a normal human being, stuff like that. Now, even if we go out and approach a lot of girls and maybe get some sex, we're still far away from being a typical social guy with a lot of self-esteem that is good at communating with other people in general. That's where having a girlfriend helped me a lot: I am finally "obligated" to really get in touch with another human being on a deep emotional level, because, you know, that's usually what happens when you have a girlfriend. You're sharing your Ups and Downs with her the same way she is sharing them with you. I have always been kind of cold when it came down to social situations, I didn't like listening to my friends or other people when they told me a story. I was just extremly bad at building a connection with them, there was no warmth in between us. This fucked me over a lot of times even when I was approaching in a club, and it also fucked me over a lot of times when I actually had dates with women. They were just not comfortable around me, which is why they dumped me. Learning to take care of my girlfriend, listening to her problems, but also being open about my own problems towards her – it made a tremendously huge difference in the way I interact with people. I simply wasn't able to achieve this by approaching more and more girls and fucking some of them.
  2. A lot of people in my social circle knew that I was bad with women and that I was still a virgin. And it spread. My male friends knew it, and some female friends that were around us now and then knew it too. Well, let's be real here: this is going to put you down really low in the hierarchy of your group, and nobody wants that. When I finally started to approach women (in front of the eyes of my friends) and lost my virginity (well, that didn't happen in front of their eyes), it got a little bit better, but you know how this works: it's hard for people (especially for your male friends) to accept such changes, so some of them might try to put you down. It's just the way we are programmed, no hard feelings. All of it changed when I finally got my first girlfriend: from now on, nobody was able to deny the changes that occured in my life, and suddenly, I gained a huge amount of respect in my social circle. It should be pretty clear that my female friends noticed it too. I don't know what it is that women find so interesting in a man that is taken, but yeah, let's just say it sheds a good light on you.
  3. When I was approaching girls, my mood was extremly dependent on my successes. When I knew I wanted to go to the club on the weekend, I was always anticipating it like a huge event. It was the same for dates or anything that was related to this whole process of getting a woman into your bed. It didn't take long until my entire life circulated around this process. As I implied above, my problems didn't disappear by approaching more girls, receving more numbers, having more dates and finally having sex with more women. Not only were they still there, but due to my need of overcompensating for the fact that I was basically a failure at life in the past, I "successfully" managed to generate a lot of new problems in my life. But I didn't want to stop, I didn't want to lose access to pussy. Even though my life somehow got better due to finally getting girls, it still was a mess, and I still felt like a failure. How is a girlfriend going to help me with that? Well, having a girlfriend means having access to pussy nearly every day. I don't have to go out anymore. I don't have to win girls over anymore. I just don't have to take care of that part of my life anymore, which means that I can finally and peacefully take care of other problems in my life without having the fear of missing out pussy. If you're the type of guy that is having huge issues next to having issues with girls, I can't stress enough how important this part is for you and how much you are going to benefit from it overall.

I could probably find a lot of other examples and I could especially elaborate further on the first point, but I guess this is a pretty decent overview.

Tl'dr: Long-term relationships can be extremly beneficial for your overall development.