I've previously bounced between different open-source notetaking apps but the great thing about any note format based on Markdown (Standard Notes/Obsidian/Zim/etc), is that it's pretty easy to move from one platform to another if they stop being maintained.

Although in the end I ended up with Microsoft OneNote (with Obsidian for special cases), Microsoft isn't going away and they don't have a habit of killing core products like Google does.

Yes. I almost settled on Microsoft OneNote. I just don't like several things of it. The writing and reading experience is not great. And I constantly find I really need one note to belong to multiple categories, but OneNote forces me to think where to save a note (which leaves me writing fewer notes).

A solution to that is to have a fleeting / unfiled notes area where you write notes and to have a separate maintenance process where you file them. OneNote also lets you link to notes internally, so you can have a dummy in one place and a link to the actual note in the dummy.

The beauty of Obsidian (at least) is that it does not matter whether the company is still around. It’s your files in a standard Markdown format.

I used to think so. Now I believe it's a misconception.

Not all your notes can be just Markdown format. You will have image files. And then different apps handle image file location differently. Joplin turns attachment filenames to random strings.

Also, Markdown format is insufficient. I will need categories and subcategories, etc. And then different apps handle those differently.