you cant move scripts and other unity exclusive files to other programs, unity script developers made it only for unity, it was never designed to work elsewhere. This may also go with unity store assets as well, they were build only for unity.
if you cant move anything outside of unity then it's never meant to work anyway. C# code and other stuff should have been able to move because the assets are not locked but if they are locked like your stuff then it is only created to be for unity. As i said scuptis are a unity thing just like blueprints are a UE4 thing, you cant make these work on other engines.
he wants to bring something from Unity like scripts, nodes, models, etc to another game engine when in reality that none of those things work without Unity. A programmer should not rely only in one program, if anything it sounds like he has something that allows him to build the game without coding which is only something many "programmers" do to make a game.
Plus no this is not Hysteric, remamber when Unity sucked being a browser and it took years for Unity to do something. That is the same fate your game engine spyware is going, into the list of block programs. Your time to build games in Unity will be wasted, your money will never return and many people will give up game development because of your crazy theory of Unity not becoming spyware when Unity itself knowledge the companies bad reputation.
Yes this is the sad fate that will happen, Unity in the history of gaming has always been awful. It was so close to getting out of that dark history of itself but now it seems like they only care about Unity being profitable than anything. Also don't forget that they under the agreement can change the contract or rules. Unity can and might just change it to the point where the developers of genshin impact will redo the game into another engine, this is the fate Unity is going though.