Fix it in-browser
I'd be happy just to have a browser setting that rejects all non-standard addresses, or at least warns the user. By "non-standard" in this context I mean:
(a) anything that isn't 100% Roman characters. (Other people who use other languages would require different settings, of course. That's fine. I'm just saying what would work for me, and probably you too.)
(b) anything that doesn't have a standard TLD. Yes to (e.g.) .com, .net.nz, .co.uk, .org.ca, and .gov.au. No to rubbish TLDs like .smile and .biz and .anybloodything 'coz I have never yet seen a useful site on, for example, .shop and wouldn't miss it. Ever.
A router setting would be even better, but less likely and more cumbersome. A simple browser setting would do. And if by any chance I really want to go to a site with a weirdo address one day, I could always uses a different browser or (better) have a way to allow exceptions.
(Yes, yes, non-Roman addresses have perfectly valid uses. No argument there. But for something like 90% of us English speakers, these uses do not apply. They only cause trouble. Doubtless a similar comment would apply, with appropriate modifications to, for example, Spanish speakers.)