I mean, people always say this, but at the end loneliness is constant and eventually feels like a dark malaise.

A non-ideal partner can be embraced as he or she is as long as he provides another thing to compensate that lack (beauty, good company, good sex, money, great parenting, etc). I'd say it is like a job in the sense you do a mix of stuff you love and stuff you hate: As long as there is more love than hate there is no need for a perfect job that does not exist, and quitting that one for a supposed ideal one can be a terrible decision at the long run.

The idea of a perfect partner is kind of unrealistic too, and loneliness (and related mental illness) is a serious issue in the West.

Some people are comfortable alone, but claiming they just prefer to be alone sounds like coping.

My point is that phrases like "better be alone that being with a non perfect pertner" have not as much wisdom as people believe.