I haven't used Mastodon, but on Lemmy the instance you are on totally matters.

For example, beehaw.org is pretty happy to defederate. It tries to give you a more moderated and curated environment. Feddit.de is slow, laggy and often outdated, and they just deactivated federation in general (at least they said so, to me federation seems to be still working) to avoid that session stealing vulnerability.

In general, federation is pretty buggy right now, with federated posts/comments having a decent chance of not being replicated.

So the choice of instance really does make a difference. But there is no help at all up front to choose the correct instance.

And just hopping over to another instance is also not a great solution, since people are used to build their social media account. It's not some anonymous throw-away thing.

At least this is one thing that's not as bad as decades ago. Just remembering how computer illiterate most of the developed world used to be.

Most people weren't ever taught about this shit and had no reason to spend time learning about it on their own. Most of us are either professional or amateur nerds, figuring this out wasn't really that hard because of our circumstances rather than our superior brains

They have just as many braincells as you, throw that attitude away.