EF are not the ones in charge. They have a lot of influence, to the point them rejecting a proposal can be enough to bury it, but very little hard power. Kind of like the Stroustrup and C++26 situation.

The people who actually control Ethereum are client dev teams. There are two groups, one for the execution layer that runs code and the other for the consensus layer that handles the actual blockchain part. No proposal can get marked as stable and entered into an official hard fork unless they approve it.

The foundation has no say over these decisions. In fact they decided not to make their own consensus client on purpose, to make sure everyone is running non EF controlled code after the merge. And they do everything they can to encourage client diversity. It's not perfect but you can't compare it to Tezos or Polygon where one company runs everything.