Do you ever feel like devs are the last people to know requirement changes, design changes, etc? And yet are the people who actually have to make the thing and ship it on time...

I was at a company for almost 5 years (my first job too). Got fired a few months ago by my mentor/the lead dev who was there for about 3 - 3 1/2 years of my time there. He left for better opportunities, he knew the company was pretty shitty to work for. He comes back (why???) and fires me about 1-2 months after his return.
Reason why, I'm unhealthy for the company and the company is unhealthy for me (not because I'm a bad dev, cool I guess). I don't disagree (a lot happened while he was gone, but he doesn't really know what happened) but this happens after I have a "discussion" with him about how I don't know how to prioritize my work anymore with new policies regarding billables and pms and management pushing me in multiple directions in regards to what I should be working on. (There's more to this but I'm trying to finish this rant eventually.)
I'm not surprised but I'm pissed at the company for never really improving and I'm pissed at him for drinking the kool-aid so to speak.
I want this company to fail. I'm surprised it hasn't. The place was a shit show when it came to the Dev department and my old mentors return didn't help much either.
I should get over it and move on but this place was like a toxic relationship I couldn't bring myself to leave (as much as I wanted to leave and knew I should). And there's so much to unpack with this place.
I'm hoping dev rant can be a good place to unpack the shit I dealt with there over the years so I don't burden my friends and family with my thoughts.
So yeah, hey ya'll and welcome to my rant(s).