The Leviathan Maze is extremely badly designed

[DaemonX_HUN]

Basically every flaw, problem, and glitch that exists in this game crystalizes here.

1. You are supposed to do PIXEL precise platforming in a game where the camera angle / perspective is simply not suited for this. Why? A lot of times you'll have no idea if the given platform will be below you or next to you when you (try to) land. This can lead to countless cheap failures. These types of challenges would be okay in a 2D side-scroller (like in Hollow Knight), or even in a 3D game where you have free control over the camera (any 3D Zelda). But NOT in a game like this.

2. There are certain platforms (especially before the second Leviathan Core) that look like normal environmetal landscape geometry and not things that you are supposed to jump on. Yet, a lot of times you have to jump on totally random and barely noticable "platforms" in order to be able to proggress forward. This is just weak level design and route telegraphing.

3. There are certain platforms (one after the first wall running segment, after acquiring the first core) that you can only able to jump onto by basically glitching/luck. Sometimes you can jump onto them using smaller jumps and sometimes even the largest jumps do not seem to work and you'll simply fall down.

4. After acquiring the first core, the segment that leads to the second core has some timed pillars. There's two that can get out of sync randomly whenever you fall down and this is a gigantic problem because it's only possible to progress by jumping from one to the other... and if they get out of sync they won't be in sync again, meaning you won't be able to jump onto the top of the second pillar because it will be always too high. The only way to fix this is to hope that the next time you fall dawn, it will fix itself. Or you just use that "glitchy" shortcut and try to avoid the first pillar and jump onto the second one instantly, but it's not the intended way and therefore it can be quite tricky.

5. After acquiring the second core, there's a section where you have to run up the wall multiple times and jump between two walls while avoiding the spike trap. This is quite tricky because for some reason the wall run doesn't seem to work, if you are BELOW the trap, you can only wall-run ONCE, and after that you'll only able to wall-jump (from one wall to the other). This means that if you do not calculate your run pixel-perfectly, your next jump will always lands you into the spikes. But once you get past the spikes, suddenly, the wall-run starts working AS IT SHOULD, and you can do continous wall-runs + wall-jumps.

6. In the third section (the one before the third core) there are tons of small platforms that disappear after you jump onto them but they are extremerly unreliable and inconsistent. Sometimes you can bounce off them before they disappear, but sometimes you'll immediatelly fell down once you jump onto them.

[T.Lightning]

although i agree, but it's not unbeatable i got the achievement for it PRE-nerf.
as for the wall jump problem on 5. try it with War, start climbing the left side and jump when you can, there is very little time to react jump before he hits the spikes(you will be on the right side RIGHT under the spikes so hit jump fast and he should go back to the left side avoiding spikes, also he climbs higher.
6. there are certain platforms that you can 'bounce' of, you just need to know which ones.

[RCMidas]

The third section is entirely consistent, actually. Each row has a set pattern that takes like, three runs to pick up AND confirm.

First row has every other platform be solid enough to stand on.
Second row has every third platform be solid enough to stand on.
Third row has every fourth platform be solid enough to stand on.

Whilst the difficulty of the platforming is entirely too much given what is asked of you elsewhere in the game, it is also entirely optional and therefore acceptable - precisely because it is consistent (now, at any rate, since initially the normal disappearing platforms were a bloody nightmare with hitboxes).

What gets a lot of people is that it is a significant jump, haha, in difficulty from anything else they can tweak settings or builds for. This requires practice and skill and memory. Not everyone can bring that to the table.