"Duplicate content" is not a super big deal if the interlinking is right ( is not).

you can still rank websites with the same content on it. The problem is the link structure on all front ends. No Topic sorting, No smart interlinking, no recommended content and so on.

Some can be fixed easy, some needs more work. But for real, there is no incentive doing it. Front ends earn 0 more with more users.

So why should they hustle doing it?