So, honestly these businesses go where the people are and Mastadon also doesn't have the userbase of xitter.or Facebook even in their decline. My kids school doesn't update delayed openings on Mastadon. Because most kids, and a whole lot of adults aren't on there.
Businesses weren't advertising on Facebook when it was "theFacebook.com". It took a while to gain a userbase that was beneficial to businesses and entities to post there and maintain accounts.