I feel that claiming the web now consistently complies with ARIA is an incredibly bold claim, and the burden of proof is on you but you can test the top 50 websites yourself if you genuinely believe that.
> are somewhat last resort when you can't do what you aim to do with bare HTML
This thinking was popular 20 years ago when ARIA was created. Application-like behaviour, which nearly always means JS, is the majority of websites.
> ARIA attributes were somewhat harmful
Wasted engineering effort on minimally effective outcomes is harmful.
> "software has had 50+ years to be bug free, let's put the burden on the users to deal with it since obviously developers can't do bug free".
Others not following your religion is not a defect.