Study finds that being muscular does not increase attractiveness for short men.

https://www.psypost.org/2023/01/interactions-between-height-and-shoulder%e2%80%91to%e2%80%91hip-ratio-influence-womens-perceptions-of-mens-attractiveness-and-masculinity-64769

One of the biggest takeaways of this study is that "while larger upper bodies boost attractive ratings for taller men, they don’t appear to have the same effect for shorter men."

If I read this right, the TL;DR is basically:

If you’re tall, you’re pretty attractive but could make yourself even more so by building your upper body.

If you’re short, you aren’t very attractive and building your upper body probably won’t help.