The way follow works for legacy social apps is it just directing to a web app, or a protocol handler (mobile).

So a follow button either has to be opinionated as to which web app it uses, or, use a protocol handler for similar UX.

Adding an extension rquirement, which can't even be used on mobile, isn't achieving the same UX... so why bother?

You could be unopinionated with PWAs using a protocol handler, but the problem with that is PWA's are constrained to the kinds browsers already support (and we still havent gotten lightning: added after all these years so probably not going to happen)

I think if people are really hung up on being not-opinionated on which Nostr app they direct people to then either making a more concentrated push on new types into the major browsers is required, or a hostile takeover of an existing one like magnet: that can decode relay/npub information