if you don't mind using an electron app, and don't want to pay for the service, and want some privacy with an all-in-one notes tool, then https://www.getoutline.com/ is probably your best pick. it is essentially a self-hosted open source version of https://notion.so - personally i use notion as i can't host my own server reliably (they have a paid option, but the free works perfectly fine if you aren't intent on organizing wikis with large teams).

but as much as it pains me to say for my personal use, i am in the process of switching back to evernote (using the nixnote2 client), as the growing numbers of electron apps on my system are essentially making my computer move at snail speeds (they are massive resource hogs). nixnote2/evernote is definitely not good enough for me and i do prefer my privacy and FOSS, but there just aren't any non-electron live sync note apps available that will work with all mine and team's devices (linux, windows, ios, android). as i share my notes with a small team and there just aren't any options out there for my needs bare nixnote2/evernote (which is not good enough by a long shot, as i actually need faster sync and live collaboration (and preferably encrypted), but for now, it's the ONLY option i can use, and i hope some day there will be a fast non-electron all-in-one notes app with live collaboration outside of the apple ecosystem).