tldr: I feel that in a lot of 3D games, on harder difficulties, the challenge comes down to too much chance, hope, and luck which leads to frustration, rather than "skill building" through conscious design. Alternatively, 2D games and turn-based games can juggle difficulty better because of the predictable rules, and because the sightlines provided gives the player better awareness. I also feel top-down viewpoints offer better rules for building player skills (like RTS-games).
I ran into this problem with Doom Eternal, and it made me think about my experience with harder difficulty modes in 3D games. Usually, I will tell myself I need to get better and keep grinding until I get through, but I now think this is the wrong way to approach this. In Doom Eternal your skill depends on timing and movement around the level, dodging, staying in areas where the demons have a limited potential to hit you, and so on. But because of the speed of the demons and the battles that involve many enemies at once, the chance to skillfully move and strike seems to more arbitrary than it should, it takes too long to memorize the arenas and learn where all the demons come from, and it becomes a battle where you end up just doing an area 20 times over and over, and hope that one of the times you take out the most dangerous enemies early before they over-complicate the fight.
I feel that the interesting and fun parts in 3D games have a tendency to break down at harder modes. You are glad you broke through the hard part, but it didn't result in a feeling of betterment or satisfaction, you are mostly just glad you don't have to do that fucking part again.
I find that frustrating, and I notice the same while playing most of the top 3D games on the market, even God of War has some really annoying parts on the harder difficulty that feel poorly conceived. Most will think of the From Software games, and I do feel those games are better tuned, but there is still plenty of parts where you fight many enemies at once and the game starts to struggle. Sekiro is the best at this because of the speed you can get away and regroup, but Dark Souls and Bloodborne certainly struggle when you face many enemies at once, as your ability to predict all of them is too poor, and the characters take a while to recover from rolls which leads to unforeseen hits. However, the From Software games are smarter in designing levels that are usually tight and understandable than most games, which reduces irritation when facing many enemies even if it's punishing. But it's still there in some form.
I guess what I am trying to say, is that the limited awareness and un-predictable nature of multiple enemies ruin many harder difficulties in too many 3D games, that there is something here that developers haven't figured out yet. It instead becomes a situation where you "sometimes win, sometimes lose", and you just have to do it over and over until you push through, rather than actually becoming better and feeling accomplishment from it.
I don't get any of those negative feelings from games like Cuphead, or StarCraft, or League of Legends, where the skill levels are understandable no matter how punishing. Simply put, too many modern 3D games overlook what is annoying difficulty contra meaningful progress and just scale difficulty based on harder enemies and less health.
