To throw them in the same pit, they're taking a page from Apple's playbook: the privacy benefits for the user will justify any market effect from closing the platform and keeping all user data internals. Platform owner gets to protect the user from some of the abuse, while gaining a critical edge on the competition.
In the current climate, I'm not sure there is any good angle to solve this, short of strong regulation limiting the advantage they get from doing these "privacy first" moves (basically find a way to forbid the platform owners from using their own users' data...I'm not holding my breath)