Oh, trust me, the arena designs are sometimes painful even for people who don't have visual impairments. (E6S and P3S both wave hello.) Even if people in this thread might see eye-to-eye on literally nothing else, I think everyone can agree that Mistakes Have Been Made with regards to some arena designs in the past.
So, anything else aside, the game does not scale stats well... and I don't think on-level trials sync your ilevel at all, at least not that I recall.
The Final Day could demonstrably be a challenge for the average PUG with part of the group down during the first week Endwalker was out, when people had at best i570 gear (if they'd finished the game and ground tomestones of aphorism in order to get a Moonward set); most people who were coming in there, especially if it was for the first time, had i560 left side and then right-side accessories lower-level than that, putting them far closer to the i540 minimum ilevel required.
Nowadays, if it comes up in roulette, you might have one or two new folks, but you've got a tank and two healers in i600 savage raiding BiS gear, etc. And even the new folks might've bought themselves a full set of HQ Classical gear (i580) that they equipped upon hitting level 90.
I can queue into Aglaia as a healer and see that my co-healer has literally nearly 10k less health than I do, because they're in the minimum gear required to queue in and I'm in BiS with an Asphodelos weapon.
That sort of gear progression does trivialize a lot of mechanics.
Plus, even in content that does sync your gear ilevel, the ilevel syncing in this game is... let's go with "a little wonky".
The Crystal Tower raids aren't a faceroll because they don't have mechanics; there's all kinds of mechanics in there. Quite a few of which would probably wipe the average roulette group! It's just that we never see those mechanics, because the ilevel synching makes the content more or less a joke.
Now, there's certainly an argument to be made that this is a problem, inasmuch as content that gets balanced to be possible to clear at the minimum ilevel required can become quickly trivialized by better gear -- and not just "this is slightly easier" but "we can skip large portions of the fight".
I won't lie, I definitely know sprouts who have been disappointed by the Crystal Tower raids being built up into this big challenge, only to basically have it be a mindless mob rushing onwards. (My FC has organized synced min-ilevel-no-echo runs of old content for folks, to try to restore that feel of danger and challenge. The old Praetorium, prior to its reworking, was actually pretty intimidating in places if done MINE. To say nothing of Coils.)
But I think there's an important distinction to be made between "this content is balanced for the minimum requirements but allows you to vastly outgear it extremely quickly" and "this content is designed from the start to be a complete faceroll".
Because they are different issues, and have different solutions.