There are good arguments from both sides of the fence in the “generic solution” VS “custom solution” debate. I think the decision should be made on a case by case basis after sufficient analysis has been conducted. For example, I wouldn’t do an RTS/Total War type game in either of the 3 aforementioned engines. Also it should be noted that sign of the times is that we’ll be getting less AAA games, not more. It’s clear that those huge budget games carry substantial risk if not successful (hence early incremental updates, DLC, mico-transactions etc.) and studios are weary of that.

For CD Project the move to Unreal might make sense just from labour market perspective - it’s easier to hire programmers for Unreal than to train programmers to learn and develop your own in-house engine. Larger community and support already exists for Unreal etc. That move will affect their bottom line on their next games though. 5% is nothing to scoff at for a big product from a big company.

In any case, I’d advise caution to companies relying entirely on a single platform for their business. To echo my previous statement choosing only between Android and iOS for mobile is an illusion of choice. If you’re a mobile game dev your entire business relies on two relatively hostile companies.