Video game development is largely grunt work outside of the engine
I don't really buy the supply/demand argument everyone else is saying here. The end product just doesn't provide value to people's lives. The amount of effort you'd need to put in to provide value to someone's life through a video game is way higher than the effort you'd need to put into a productivity tool.
In fact, more often than not, video games provide negative value to people's lives. They're usually a waste of time at best. And at worst, addictive and carpal tunnel inducing.
I'll concede an email app doesn't produce that kind of wide-ranging effect on humans.
So bringing this back to the "why don't game devs make boatloads of money like FAANG" it's because the vast majority of roles are being a scripter at Game Freak or Rockstar or whatever. I'm sure the engineers at Valve or Roblox or Epic Games are being treated very well because those companies actually provide value to people's lives.
Roblox to a lesser extent, but you get my point. I'd rather have my kid play Roblox where he might learn Lua scripting, than Pokemon which is just a complete dead end. Just look at what happened to Byuu and Hax. Or hell, even endrift with that weird unnecessary drama with Analogue. Many such cases. Not sure if you get those references. But the stories surrounding those people are why I stay far away from Nintendo stuff. And gaming in general.
You're waaay too tuned in to the corporate ideology to be saying something like this. I suggest you zoom out. The top heavy games do make a ton of money, so evidently there's value in entertaining people and giving them some good playtime compared to the drudge that is corporate life (PS. in case you didn't know not all people love to work for some other guy's mission/vision).