Which part of the industry are you talking about? Final Cut Pro is most definitely not the most used by television and film studios.

The Avid/Nuke/Maya stack is far more popular, in that realm. Followed up by Adobe’s stack on the lower end.

yup. the Nuke -> Avid -> Resolve pipeline probably covers at least 80+% of post-production in film and TV.

on the VFX side, Maya -> Mari -> Clarisse is still overwhelmingly common unless it's a studio that has their own custom tools. Throw Houdini in there for good measure (starting to replace Clarisse more and more for lighting and scene assembly).