Now that I'm remembering, I should officially submit
EWTRTW for this
Admittedly the backing for the tier isn't that strong, but paradoxically I'd say that's apart of the best argument for why it should be allowed. It's a collaborative project between a lot of people that just escalated extremely hard in it's insanity. Initially the Tier 1 ratings were based of scaling to stuff that inexplicably just showed up in what I remember being Thread 12, which was so insane that the literal presiding God of the game looked over and retconned it (as in, used their explicit ability to warp reality to their favor) to be a result of people sniffing too much of a chemical leak.
The more current justification I'd use for any page updates that inevitably are needed is NACHILLEMORAC
going up the infinite dimensional ladder until he nearly breaches the Omni's domain, before just being retconned, which in turn was mostly as a result of 4 going insane and keeping consistent with the previously (insanely) established lore of Omnis just kinda scaling that high
Admittedly actually digging up the NACH evidence did make me realize that even just as a justification it's literally just an offhand line like "yeah ugh High 1-B that happens moments before reality is assimilated and NACH dies to being retconned and the net entry has Joseph just quit the game", but I can provide an alternative if that's unsatisfactory
in Die 1, the protagonists break into the base of Nil, a Lesser form of Omni's race that still has access to Retcon but in stature is a lot weaker. Puncher McFucker takes him out, then realizes the universe is actually a fake, being presented
on a "Soundstage" that he proceeded to rip away to reveal the genuine Nil recording everything as a work of fiction, with his entire deal up to that point being a cash-grab godtuber trying to wrap up the story he's seeing unfold
Either way, the important part is that there is a justification for the rating, and it wasn't just made up to make the characters strong, but just to emphasize the extreme and comical escalation that embodied the series throughout it's runtime