This ignores the role of regulators e.g. EU. ActivityPub is the first glimpse at a future where social media networks are interoperable over a common standard

This ignores the role of regulators e.g. EU. ActivityPub is the first glimpse at a future where social media networks are interoperable over a common standard similar to mail. And from recent history the period we are in is one in where governments are looking for open standards as a hedge against big tech. The idea that Meta would deliberately harm a standard, shut down competition and invite anti-competition investigations is far-fetched.