If you comment in r/conservative, even as someone who isn't subscribed and just happened to end up on the post due to r/all or a crosspost, odds are you'll get hit with a number of bans on other subreddits.
This is for the same reason that mastodon's federation works the way it does: those other groups do not want to associate with or interact with accounts that talk on or interact with these certain communities.
If you interact with a toxic subreddit that has a habit for harassing other communities, those other subreddits likely will ban you just to save themself the trouble of dealing with someone who might bring them more stress or hassle.
Likewise if you federate with a toxic instance or are hosted by a toxic instance, other instances will block yours and you'll be cut off.
The only extension to this is that your instance can do the same to others. But that's really not that massive of a concern as you can pretty easily just move to a new instance or better yet, host your own instance and not have to worry with it at all.