Ok, I played with Trilium for a few minutes because... why not
First observation: from a non techie standpoint, it is virtually impossible to get started. You have to visit Github, read all the instructions on how to visit the release page, then fish out the correct version, then extract the ZIP, and then find out from a huge list what file to start to run Trilium. That is a far cry from the installations that user friendly apps offer. Take Joplin for example: you visit the website, click a huge "Download the app" button and 30 seconds later there is an icon on the desktop that allows you to get into the app.
So you finally manage to get Trilium going, and the next hurdle presents itself: choose a username and password. It turns out that this is not some online account as you would presume based on previous experiences with other apps, no, it's just to set you up on your own computer. Ok, fine. You enter your name and some password, and finally you're in the app.
Whoa! I think I accidentally opened someone's note app! What's all THIS cr@p???
Enough for now... I'll look at that later. Close the page, pfew, good. Let's try this again. Wait, how do I get into the app again? There isn't anything on my desktop, nothing in the Start menu either. Ahh I have to go back to my downloads folder, find where I unzipped the Trillium folder, Find that thingie again that starts the app, done.
Let's try a new note. Hello! Testing! That went well and I like the formatting options. Playing around with it a little things become clear(er) and I like some of the features a lot, but... it's definitely one of the more "geeky" solutions out there. No idea yet how syncing works and if there are any Android/iDevice apps out there, or web clipping, or plugins... but... I'm pretty sure it won't be intuitive either.
So all in all I can definitely see why it's attractive, and I do like their editor better than Joplin, but you'd have to be really invested to actually learn the ins and outs... while Joplin is as easy as "install, and use". Or, as someone pointed out in this thread, even granny can get the hang of it within minutes