I have two questions: 1. What is stopping anyone from using UE4? 2. Aren't engines supposed to be somewhat flexible/modifiable/customizable? This feels like the opposite of that to the point of being unusable for anything one might want from an engine. If things are as bad as you say, then UE5 cannot even be called an engine.
Unreal 4 is pretty much the same, UE5 just added Nanite, Lumen, their new material system Substrate and other mainly movie production or animation related features and under the hood changes and re-did the UI (for the worse in my opinion). You will usually get better performance out of UE4, and there are still games being made in it, but its still the same sort of 'its made for what Epic needs' as UE5. UE5 is not unusable, it does its job, but if you have a particular vision or actually care about the quality of your work you will be limited by what it provides. For indie devs because it provides so many existing systems it can be a godsend, but its a double edged sword. You can have a game use Unreal and not need Lumen, Nanite, TAA or upscalers and still look good, but you need someone who actually cares about their vision to put in the effort, that's unfortunately not the case these days, with most developers, AAA and indie, just using whatever the default settings are and just rolling with it, either because it looks 'good' with no work or because they don't know any better, which is how we end up where we are now with games being so reliant upon blur filters and having poor performance. It's part of the competency crisis, the barrier of entry has lowered and the people coming in don't know or don't care enough about their work to put in the extra effort.
Unreal's source code isn't documented, and comments are kind of sparse, not explaining how systems work at all. So while you can modify it to suite your needs, its going to be a lot of trial and error. I've messed with it myself a bit and have managed to do some things I needed, but its always a struggle, especially when the few engine code tutorials that do exist get outdated fast when Epic decides to change random functions for no reason.
Unreal is so popular because it has 'photoreal' graphics out of the box, because its free to use, provides free assets with megascans, and that means a bajillion pajeets can learn to use it and you can hire them without any training required to learn internal tools. Why spend a chunk of your budget developing an internal engine and toolset that requires you to train new staff when you can just use Unreal and pay Epic 5% royalties.
) and overpriced w/tons of DLC. Then they said "oh yeah, we're moving on, here's ARK: Survival Ascended! It's exactly the same game, only ported to UE5 and with all the DLC ripped out so you can buy it again! Yay us! Also don't mind the shitty performance, we're working on it! Also also, all official ARK: SE servers are offline now, toodles!"
