Why is Unity the most popular engine?

Oh yeah; let’s invest 8 months of development effort to build editor extensions for an engine that we are paying $200USD+ every month! (I’ve actually done this more than once for myself and companies; smart me! smart company!)
So then we can finally start making the game we want to make once the engine has these basic tools that are supposed to be in there by default; Or we can pay for more assets so we could start making the game right now (but then comes the problems with such paid assets not working well with each other)… That’s . Best engine ever!

When people talk about Namespaces I wonder if just naive or actually have never ever paid for a bunch of Asset Store packs and tried to integrate them together because your boss wants “this and that, with that and that plus more of that”…