Hahahaha

Had someone like you on an improvement plan. Man was "senior X position" (don't want to reveal too much) but was incapable of managing his workload, achieve goals, or plan a path for a project. However his "senior" job description included all those expectations and that's why his position was many many thousands more than a regular position. He could only do stuff if you told him A, B, C. Which even someone not in his specialty could do, let alone juniors.

Yes, the improvement plan led to him being let go. With plenty of cause.

Improve yourself, sounds like you've been skating by.

But you didn't post a TIFU right away along the lines "omg, TIFU by asking for more help for our team and getting my boss fired instead". Oh no, you are here crying because you are getting your just rewards - getting fired. You didn't really care that she was fired until it became worse for you.

You were there 10 years and somehow were not very knowledgeable about expectations or your higher ups.