This. Without going into specifics, I attempted to internally transfer to another team for higher level/better pay position. My current boss said he doesn't have a problem with it. I pre-cleared everything with the possible new boss, but I got mysteriously blocked. Few months later, team member from the other team indicated that they were told not to let it happen ( and who said no ).
Needless to say, I am miffed. The market is what it is right now, but not only am I not 'allowed' to move around, but stuck with the same pay/benefits, because my raise was.. lets say not great.
There is not enough .. not hate.. not enough awareness of how corps fuck you over and HN can help with that a little.
I've seen this but with the guy's manager being the blocker. Manager tells high-performing employee that he's gone (probably for some BS personal reason--the guy was good), but company policy is that he gets two weeks notice before his last day, and if he can find another team to transfer to, then he can stay. Well, since he's a great employee, multiple teams are interested, but Manager blocks them all, and the guy ends up having to leave.
Calling out internal mobility (and normalized support for taking advantage of it!) as a key corporate culture value.
I've worked for companies that make this hard/toxic/impossible and companies that make this easier/normal.
The latter are always better, healthier companies.