Stalker 2 has made me look back and realize that maybe it was a mistake to make Epic Games' Unreal Engine 5 become an industry standard for the next decade.
I don't agree with this at all. I'm sure there are projects where it wasn't a great choice, but I've had no consistent problems with UE5 games, and in several cases the games look and feel better after switching -- Satisfactory is a great example.
Dead by Daylight switched to UE5 and immediately had noticably bad performance.
Silent Hill 2 Remake is made in UE5 and also has bad performance stuttering. Though Bloober is famously bad at optimization so its possible it might be just Bloober being Bloober.
STALKER 2 is showing some questionable performance issues for even high end PCs, and that is also made in UE5.
Now, just because the common denominator for all these examples is UE5 doesn't mean that UE5 is the cause, but it is certainly quite the coincidence that the common denominator is the same in all these examples.
It's the responsibility of the game developer to ensure their game performs well, regardless of engine choice. If they release a UE5 game that suffers from poor performance, that just means they needed to spend more time profiling and optimising their game. UE5 provides a mountain of tooling for this, and developers are free to make engine-side changes as it's all open source.
Of course Epic should be doing what they can to ensure their engine is performant out of the box, but they also need to keep pushing technology forward, which means things may run slower on older hardware. They don't define a game's minspec hardware, the developer does.