No...t entirely.

There is a lot of extremist propaganda here - e.g. advocating for literal murder (just search for the word "guillotine" to quickly get an idea of what I mean). Also, if you criticize Russia or China on lemmy.ml, or try to claim that e.g. genocidal practices happen (even share your second-hand accounting of Uyghur family members) you will get banned from communities that you've never even heard of across the entire instance, with no prior warning.

The "funny" part there is that both Russia and China are capitalist nations, not communist. It helps to think about children talking about what they think (or rather wish) communism is, rather than the real world. So they'll tell you to read certain books, while studiously ignoring e.g. that the Tiananmen Square massacre actually did take place, i.e. they cherry pick and only talk as if they care about it, rather than actually doing so. Think Truth Social, but claiming to be leftist rather than right.

But e.g. there's also Star Trek memes, and... well I am sure there are other things too, somewhere!?:-D More seriously, each instance has its own focus, none of which (anymore) is "conservative", all of which is left leaning, but the vast majority of which is not extremist. Mander.xyz for instance has some fantastic scientific content.

Check out !newtolemmy@lemmy.ca - I refer back to it often, e.g. to remember how to do things like use links to communities from different Fediverse instances. I wish it, or something like it at least, would be shared with everyone, but Lemmy is extremely primitive when it comes to such things (case in point, if you go to lemmy.ml, visit their sidebar, and click "What is lemmy.ml", it takes you to a post that does not exist).

I have been advocating for labeling such communities and instances - that way, like porn, people can enjoy it all they like while also being friendly enough to let others know what's present therein, and that way we can get along better. However extremists famously resist labeling themselves as such, treating their own views as the sole correct one and rather it is everyone else - yes literally the entire rest of the fucking world - that is "different". So instead, each person has to find out mostly on their own what these subjects are all about. Kudos for sticking around long enough to do so.