Apple is adding desktop applications to iPadOS and making iPad more desktop like - as large group of users (here and elsewhere) have been noisily asking for... For years! - result : Welcome Preview.app with its macOS functionality.
Now the other side is noisily complaining about iPadOS becoming more desktop like and getting new applications from macOS.
Welcome to the world where whatever you do, people are complaining ;-)
I am actually amazed, how Apple managed to make functional hybrid. I can switch between old iPadOS behavior and new desktop-like behavior easily, when I want. Takes some training, but it can be done even with old dog like me...
Anyone can switch between these behaviors (look it up or ask AI on Google) and never use the $select:"new -or- old" one, if they wish. Use Files.app or Preview.app, whichever works for you better, there is small difference between them. I personally prefer Preview since it is similar to MacOS.
My next iPad will be 13 inch since 11 inch is too small for this new windowed behavior which works actually really nicely. I guess Apple will have earlier hardware upgrade than I originally planned simply due to iPadOS improvement.