It really isn’t such a big deal. Switching to A4 would mean replacing every single binder, folio, cover, and clip in the country, and for what? A slightly taller sheet of paper? US printers can already print A4 if necessary without any issue.

I think the UK has done that - I have foolscap and letter folder from the 70s. And no we did not replace every binder, folio etc.

We just bought new ones when needed.

This is just obnoxious. If you really do live in a much, much better country, then why don’t you get offline and enjoy it instead of spending your time trying to convince Americans that theirs is so much worse?