The damage has been done though, I doubt any developers will put their eggs in this basket after they've shown themselves willing to destroy all of their customers business models
It’s not just changing gears. It’s the amount of time you have to invest in it. Changing engines mid project when you already have half the game finished could easily cost months especially when you still need to learn the new engine. That’s months that could have been used to finish the game.
Or they're a small team who literally can't afford to switch engines without killing their studio so a switch has to be carefully planned and could take years. It isn't just greed and sacrificing morals keeping people using Unity
It's not that simple but yeah if things keep going this way more people will keep moving away. The ones that remain are likely to get hyper focused on to keep the user base in the same way you have to increasingly cater to whales in a game after the community at large leaves