I know this is not the first time this is requested, but that was a long time ago. Please hear me out.
I propose the option to link between notes is critical and should be a part of the main app, not just a plugin. Or, it should be a part of the mobile app, if not the desktop one, since there are no plugins on Android.
The feature does come up in discussions (like this one). There are old feature requests as well, like here or on github.
The stance I got from those was - if you need that feature, use a plugin. Initially, I agreed wholeheartedly. I have always wanted my note app to have two features - quick linking, and a list of links back to the note. When these became available, I have completely changed the way I take notes.
Whenever I write a new note now, I try to link it to an existing note. This, combined with a view of backlinks, make capturing ideas and connections between them a breeze and became an integral part of how I take notes and think about them. It also makes them more useful, since it's less probable I will write a note and never stumble upon it again, leaving it forgotten.
But now I find myself using the Android app less and less because of it. When I open the app to jot something down, more often than not I close it again without doing much, because I find that in order for the to make sense, I have to link to some other note. Sometimes I solve this by making the note into a todo, and adding links on PC later, but this is annoying and unnecessary.
(Let's disregard the Backlinks now - they're helpful/necessary for extracting knowledge from notes, but I can live without them on my phone; they'd have to be hidden in some menu anyway, not glanceable as they are on desktop.)
It doesn't matter to me much how the UI would work, as long as I could insert a link without leaving the note currently being edited. The @@
syntax is great on desktop; for the phone, maybe a menu action that pops up a search that lets me select a note would be better?
Will you maybe consider this again please, @laurent?