Concentration of power is (or at least I thought it was) obviously bad. This is why there's laws protecting against that but either they're not enforced or they weren't updated to the internet age.
It is a concern but being popular is not the same as having high power: GitHub has lock-in to the extent that it's a great service but it's not exactly like they're changing Git to prevent you from using your own self-hosted service, Gitlab, BitBucket, etc. Similarly, VSCode is open-source with tons of competitors: where's the angle where they have much ability to dictate anything to users?
