A kind observation that exclusively calling this place "Mastodon" has a bit similar energy as saying "I just sent a GMail."
"Fediverse" (or "fedi") is a more inclusive, general term.
Mastodon is just one of many software projects that talk to each other to create this multi-instance social network:
https://axbom.com/fediverse/
(kudos to @axbom for this fantastic infographic!)
There are blogs, Reddit-like communities, video instances and many more, all part of fedi.
@YusufToropov sure but if we call all cars "Toyotas" then people will not even know other makes exist. So putting this little fact out there every now and then makes sense to me.