After looking in vain for a browser-based Logseq (i.e., the way logseq used to be before APP EVERYTHING!!! began the downward spiral -- the next version won't even use markdown files), I've gone full Leeroy Jenkins on Silverbullet. It's not refined. It's not stable. But it's good enough, it lives in a browser, and it creates markdown. It's also incredibly customizable with Lua, but that's not necessarily a net positive for someone who wants an environment that works simply.