Seems of limited use considering Unreal Engine's source code is available, and UE is probably a better engine and also legal to use in your games (albeit only for a percent of royalties).
Like, you still get "asset flip" games that copy default projects, but they are background noise. Having the source to something large like CDPR's games doesn't mean you have access to the studio infrastructure of CDPR.
By and large I suppose I agree with you.
Star Wars Jedi Fallen Order
Final Fantasy 7 Remake
Days Gone
Code Vein