Mastodon.social is the address to that specific Mastodon instance. Take a look at this site for more info.
why not make everything (instance).com?
I’m not exactly sure what you mean by that? Are you suggesting everyone to use a ().com? If so, because they are rarely available and if they are, quite expensive.
But we aren’t talking about “people”, we are specifically talking about Trump. Trump didn’t “evolve”, he’s a swindler who will say whatever to whoever when it benefits him.
So let’s not take normal people finding out more info on a topic and pretend like that has anything to do with nonsense he happened to say one day or another.