> Meanwhile there are still millions of projects done with OOP, including super-complex AAA games I've heard that OOP in game engines is in decline with so-cal

> Meanwhile there are still millions of projects done with OOP, including super-complex AAA games I've heard that OOP in game engines is in decline with so-called "Data Oriented Programming" taking over, that Unity's inheritance class library was a disaster, etc. So, it's not FP per se, but a focus on data over "objects" is a big part of FP being about "values" instead of opaque state.