@Mastodon it is not analogous to GoogleTalk and FB Messenger embracing XMPP then ditching it when they get enough traction.

It is more akin to Microsoft and Google offering email services and gaining such a dominant marketshare that they have rendered deliverability of email from small independent providers extremely difficult, to the point that even seasoned IT professionals are giving up and using Microsoft or Google platforms because managing your own server has become too difficult.

Yes, we all use the same SMTP protocol, but some SMTP servers are more equal than others, no matter how careful you are in picking a clean IP, setting up SPF records, DKIM signing and DMARC policies.

A handful of big players are taking control of the e-maik federation.

l sure hope ActivityPub does not suffer a similar fate.

With Meta "embracing" (first E in the proverbial EEE strategy) the Fediverse, the most obvious targets are microblogging (Pleroma, Mastodon, Calc/Misskey) and image sharing (PixelFed).

The concern of concentration already existed with larger instances like mastodon.social, but Meta entering the chat is a whole nother level.