U2F was made for a different purpose too.
I don't see what's so extra hoop-y about telling SSH "use key from industry standard PKCS#11". That's literally what it's there for, and when Yubico added PIV support that instantly added support to multiple operating systems (incl Linux & Windows) where SSH keys "just work".
I can take a yubikey today from my Linux system, plug it into a Windows machine, and Putty with wincrypt support "just works". Because that's how it was designed.