I avoid the word "scale" and see that mostly in light of Big Tech services conquering market space. In a decentralized web "Small is Beautiful" (E.F Schumacher) and 'smallness within large organization' to be sought.
The 5 years since spec Recommendation status saw slow organic emergence, not spec evolution. The emergence was valuable, needed, to foster unique culture and social environment.
"Substrate formation" by the Commons is needed for open ecosystem.