Burnt out with polyamory

I (26M) have been poly/RA for 10 years now. I've always been in it more for the political RA side of things (I don't think romantic partnerships should be automatically more important than platonic relationships), but I've been through so much shit and seen so much stuff it's making me question my sanity.

I've had people break up with me to go mono with someone they felt they finally clicked with. I've seen countless people being sidelined by their partners because of NRE, including a friend who had to break up with her BF of 8 years because of how bad it got. I've had a girlfriend I was discussing becoming NPs with ghost me and marry her ex. I've watched an entire non-hierarchical polycule with 10+ people collapse because one person had a hierarchical relationship they refused to acknowledge and it made everyone uncomfortable. I've seen several people take the STI prevention requests from their partners personally, and basing their safety on trust until someone on the polycule got an STI.

I feel like most people in poly, ENM and RA are just using it as an excuse to have no emotional responsibility and keep people around despite their commitment issues tbh. I'm not saying this is an issue with ENM/poly/RA, but it's definitely an issue with the people drawn to it and I'm exhausted.

I just want a nice long-term relationship where the existence of other partners is a non-issue and we can talk things out like adults, is that too much to ask? At this rate, the only reason I don't swallow my pride and go back to being mono is because I don't want to go fully platonic with my QPPs.

TL;DR: I still think poly/RA is best for me but I'm tired of people being emotionally immature dinguses.