I tried the expensive non-FOSS RoamResearch and was sold on the idea of non-linear note taking. I’ve since tried TiddlyRoam but have found it too fiddly compared to what I was using before (OneNote). It’s quite the big switch to make and I need full confidence and commitment before attempting to switch platforms…
tiddlyroam is another David Gifford production, which he updated to make Stroll. I agree that the approach is fiddly.
what I would say, though, is that if it were me, I hate starting from scratch, so I’d play around with what I could do with converting the notes I already had. it’s ugly, but this talks about how you can export from one note into evernote, and then from evernote into Joplin. Joplin is FOSS and already pretty cool, but like I mentioned, I’m not the biggest fan of the link syntax–so from there you can export into markdown files. Markdown files are super portable so from there you could try vimwiki, obsidian, my tiddlywiki setup, etc etc.