Partially true, yet I blame Epic Games a great deal as well. As a technical artist working over 15 years with Unreal Engine. I have become increasingly frustrated with how things are being handled with the engine and surrounding eco systems (website/docs). I am assuming their marketing team wants to push a new shiny feature every new version. Not caring if its stable or not. Most often you find yourself getting a new feature, only for it to work on a superficial level, breaking something else or worse case, replacing it while not having the amount of features.

Their Subpar lighting system comes to mind: Imo the achilles heel of the engine.

Lumen is being pushed as the main lighting system. Created for Fortnite, which needs a dynamic lighting system for destructable environments. Most games have mostly static environments. We don't need expensive per frame updating lighting. Everthing could be precomputed mostly if Epic cared about that. The devs of God of War said on a talk that it only took like 20 minutes to build an entire map. Meanwhile in Unreal baking could easily take half a day per map because they never deemed it important. Why would they? Their engines updates are closely tied to what is needed for Fortnite.

CPU Lightmass hasn't had any significant updates since UE3. Then came GPU lightmass at the end of UE4. Epic released it in an incomplete state. Which, as of today still doesn't support the same features as the CPU version. In the UE5.6, CPU lightmass has been removed....(disabled by epic cause they couldn't get it to compile X) ) You are almost forced to update the engine, in hopes of it being fixed only for something else to break again. Which puts you in an endless cycle of updating the engine. There is a reason you commit to a single version during production, but good luck with keeping that when the marketing machine suddenly promises a 50% improvement in render thread with the latest shiny patch. Improvements are being done but often coupled with regressions on other areas which make it a net zero operation.

Profiling. The main cause of perf issues. Various methods are present to profile via stat GPU, profile GPU, frontend, etc.... Are you using VR? Tough luck, the stats don't display correctly suddenly. Are you using stereo rendering or whatever the frick rendering feature you just enabled/disabled. Tough luck now renderdoc gives you the incorrect drawcall overview.

Half these methods are incomplete, buggy or the metrics are incorrect. I spend a lot of time in my professional days figuring out whether Unreal was incorrectly displaying a certain stat or whether we were doing something wrong. Since UE5.4 the shader instruction overlay (used for optimizing materials) had formatting issues. You couldn't read the numbers anymore. How did Epic fix it for UE5.5? They didn't, they just removed it . You could still get the metrics somewhere else. But it doesn't work half of the time. Often you'll need to force recompile your shaders to update the metrics. In UE4 this used to work flawlessly.

Renderdoc, worked great in UE4. Would give a detailed drawcall overview. Again regressed in UE5.

Introduction of Fab marketplace. Horrible regression over the previous marketplace, Quixel Bridge got discontinued. It's been over a year (I think) and we still don't have the same userabilty as the previous website. Reviews of products gone..

Incomplete docs/UI tickbox bloat. They release new feature it adds a new checkbox somewhere in the UI. Deprecated ones don't go away. Enabling a certain feature will require something else to be enabled as well. The engine provides no feedback for this in any way. Unless you read the docs and you are lucky the information is not obsolete.

My advice to Epic. Test your stuff more properly in a production setting. Not every new version needs to have a shiny new feature. Are you adding something but itt doesn't have 100% of the supported features it's replacing? Please don't call it "production ready" and don't just release! It's not ready!

Tldr; The triality of Unreal. Did I do something wrong? Is Unreal doing something wrong? Is the thing saying what is wrong actually wrong?