Kojima's great, I've quite enjoyed his writing for a looong time. He's a very unique writer more than anything and he's incredibly passionate about his work, a thing any artist could be praised for. And if you think that Konami's reasons for firing him were entirely justified, boy do you not understand how Konami works. The inner workings of that company are some of the most draconian bullshit imaginable.
Phantom Pain was also great stuff, though if you're not very invested in Metal Gear then it's not really a title that's necessarily gonna mean a whole lot to you. Your criticisms seem to imply you're not very familiar with the source material. It was unfortunate that it got cut short, but that was Konami's doings so just kinda gotta deal with it and that's the end of the story. Metal Gear is about to go down the tubes with that stupid Metal Gear Survive shit, so 🤷.