According to Epic Games CEO Tim Sweeney: "The primary reason why Unreal Engine 5-based games don’t run smoothly on certain PCs or GPUs is the development process" rather than a problem with the engine itself.

https://www.vgchartz.com/article/465613/epic-ceo-unreal-engine-5-performance-issues-is-mainly-due-to-devs-not-optimizing-properly/

Epic: Builds and leases out engine where almost all features and functions are built-in so as to allow less experienced developers and smaller studios to take shortcuts and cut costs. This comes at the cost of performance.

Developers: Uses the engine the way it was intended, to cut costs, outsource (pun intended), and take shortcuts.

Epic: Gott-dayem developers! 

Side note; even a long time after release, experienced developers are having trouble making games run properly in UE5 via a slew of patches and fixes. Functions like Nanite and Lumen were supposed to solve hardware limitation issues and revolutionize, but especially Nanite has shown to be a resource hog via upfront rendering loads and needs beefy hardware to get off the ground (at least that's what I hear from my acquaintances in the industry). 

UE5 made a lot of promises - it hasn't delivered on most of these, in my opinion. Least of all on causing an upturn in released games that run really well, regardless of the core issues behind it.

Another issue is developers developing for next gen for the first time, new feature sets, and ssd. They need to put in the tjme to learn to develop for new systems and while learning the new engine

Tim Sweeney has Unreal engines.

Said it in the other thread, but will say it here. The problem is neither the engine nor the developers. It's the fact that the publishers demand very rapid timelines while understaffing their development teams so that they can maximize profits. If gaming companies staffed their development teams like a health-care or social media company did, and paid them akin to how they are paid in these industries, then the games would come out well-optimized and beautiful. Instead game developers are paid the lowest of any software engineers in any industry (with the sorry excuse of "gaming is interesting and attracts engineers") and expected to do the most hours with the most understaffing. 

I've been working on a UE5 project in my spare time, for fun, and getting nanite and lumen (which I might replace with a custom ray-tracing solution) to optimal levels on a mid-ranged GPU (RTX 4060 mobile) took about 10 hours or so. When connecting an RTX 4090 (via eGPU) these optimizations/tuning scaled as expected. But if I were part of a project where I had to play catch-up on work tasks or slowed down by project managers, I likely wouldn't even have bothered, prioritizing actually getting working, non-buggy output instead as the scope creep, wasteful scrum sessions, and short timelines pressured me to do so. 

EDIT: Personally I think the best firm-structure for excellent creative, optimized, polished games are producer cooperatives like Valve where the developers, designers, and artists are also invested in the company. Some employee-friendly companies like Nintendo (who would have their executives get pay cuts before layoffs) can also emulate this, but I think that is rare. 

EDIT 2: Just to put things in perspective, Senior Software Engineers in the video game industry make at the median roughly what an entry-level Software Engineer makes for a large health-care company here in the U.S, and they're more likely than the health-care industry Software Engineer to live in a high-cost of living area. Why would talented engineers work for $90,000 per year in coastal California or Washington D.C area, when they can make $130,000 in Conway, Arkansas? Because it is more interesting work? 

I just played Split Fiction and it ran perfectly aside from like 3 stutters for the whole 16 hours so poor optimization is a huge part of it for sure. Hopefully by the time UE6 is out poorly running UE games are less common.

I don't think it's a laziness issue.

It's like asking a mom of triplets to also make a top cuisine class meal for dinner every night, while keeping the house spotless ... she's already dead tired looking after the kids all day and you're nitpicking that the dinner isn't Michelin star quality.

The scope of today's games and graphics even at a PS4 level is incredibly high and is driving teams to exhaustion to hit release dates as is, unfortunately proper optimization has gone out of the window. Something has to give and the two things that are "giving" it looks like are budgets (ballooning out of control) and optimization (no time for it, and too complex with projects of that scale).

My boyfriend works as a senior QA in a game development company, and he told me that the wages for junior and mid-level developers range from 32k to 65k BRL a year (about 6k–12k USD)

That's kind of nuts, because I'm a mid-level Data Scientist making 140k BRL a year (~26k USD). Granted, data jobs are among the highest paid (and usually require the most highly qualified professionals, at least in terms of college or postgraduate education), but it's still perplexing. The brightest minds in software engineering are probably not in game development. My guess is that the best developers, at least in terms of scientific computing and theoretical foundations, are all in software development, aiming for FAANG jobs

I can see many of the brightest minds on gaming development just giving up their jobs after feeling fed up with getting overworked for very average to bad wages

Yep, here in the U.S I make $220k as a Machine Learning Engineer and I live in a median cost of living city (Pittsburgh, PA) although my job is fully remote and there are offices all over the country (with the biggest in Texas.) 

When I was a Senior Data Scientist I was making $110k base salary and I was underpaid compared to my peers who were making about $130-$140k. Gaming industry SWE's seem to make $70k-$130k and they tend to live in very expensive regions. 

Good game engineering isn't less difficult than Data Science in my opinion. In some ways it is harder. The issue is that with middle-ware the companies want to offload all of the hard stuff onto the middleware company (Epic in this case, who pays $200-350k for their engineers) and then hire the cheapest SWE's they can find. From what I can tell the Game Engine engineers make what you'd expect for their level of expertise and knowledge (see: Epic example), but for each of them there are probably a hundred SWE's in the game industry. 

As far as I know, game programmers are highly valued, at least in some fields. I suspect it's especially people close to the engine, where the work is more technical in a way (performance requirements, math etc.), but I don't know for sure. My point is that at least some programmers in the gaming industry probably actually are much better developers than you might think at first.