I think your skepticism and concern is well placed -- the output is what matters. But I'm a little confused about one aspect: what is it that you perceive as "complicated" and "complex" in this? Genuinely curious and not meant to be snarky.
> I find watching how this knowledge graph grows satisfying
Yep, it's satisfying. Because it's procrastination and gives you the illusion of "being in control" - just like engaging in social media is satisfying. Or cleaning your room while you should be doing homework. I don't think it's useful.
Taking notes is great. Research has shown that active note taking, e.g. while watching a lecture, is a crucial part of learning. Organizing them into some (in case of roam, PAID!) system that you will probably not even come back to? Procrastination.
> active note taking, e.g. while watching a lecture, is a crucial part of learning
I agree! The word “active” is crucial here — categorising, structuring and interlinking knowledge fosters understanding. The Zettelkasten builds on this principle, because — when it works in classroom, maybe it would be good to interlink and structure your ideas outside of it as well.
> Organizing them into some (in case of roam, PAID!) system that you will probably not even come back to?
I sense a straw man here. Of course, if you don’t plan to look at your notes ever again, why bother writing them down in any kind of system?
The whole point of Zettelkasten is to write down notes that you intend to use in the future. You can still have some ephemeral notes, but you don’t rewrite those to the Zettelkasten.