It's easy to play the critic and sit back and declare that life does not measure up to your expectations. But personally I find building new things, however imperfect they may be, far more satisfying.
It's also a lot of work!
I'm at a similar place in life, especially after being a terribly critical person almost all my life. Thankfully, the best takeaway for me from my so far below-par tryst with entrepreneurship has been to be much more appreciative of everything.
All the things that are wrong are things that can also be improved, so, these days, I try to think of what I can do to improve them.
Providing well-reasoned criticism backed by evidence is much more difficult. Providing constructive criticism or suggestions that are meaningful is even harder.