FWIW the clear difference here is that if someone is banned over one thing, their ban might later be reversed if that thing is no longer considered bannable or

FWIW the clear difference here is that if someone is banned over one thing, their ban might later be reversed if that thing is no longer considered bannable or if opinions on the incident change. If they did 170 different things, each one warranting a ban, the only way for the ban to be lifted would be for each of those 170 things being dismissed individually. The same goes for doing one bannable thing but "a lot" or to a very extreme degree. Say, defacing a Wikipedia article with a bogus message versus defacing the entire Wikipedia website with borderline illegal graphic content. There's arguably no "mildly" banned but this distinction makes sense in a lot of contexts to give a rough idea of context: a corpse is dead but the scattered remains of someone caught up in a high yield explosions are extremely dead as even in a sci-fi story it would be hard to imagine them being "revived", a dainty woman might be pregnant but if she's visibly close to delivery with a pronounced waddle and struggling to get up after sitting down, it would be fair to call her extremely pregnant as there's no denying her state whereas the pregnancy might have been hard to even notice a few months earlier. English lacks a grammatical signifier for evidence or degrees of confidence (no, the English subjunctive is a poor approximation at best and mostly limited to expressing explicit doubt) so superlatives are a good way to express high levels of confidence. "I am banned" means you're banned but leaves room for the possibility that this might change or be reversed. "I am extremely banned" suggests it's that way now and there's nothing to change that and nobody will likely ever be interested in changing that in the future.