For me, the key is having one folder that I use as the inbox.
I can then use any program that saves to local files to make a quick note, with the inbox as the default location. On mobile programs may be restricted in the folder they can use, in which case I set up autosync to synchronise their input folder into the inbox folder.
Sorting into different Obsidian folders takes place later.
My aim is speed and simplicity in making the note and I do not, at that point, want to have to think about which folder it should go in. I don’t feel that Obisidian’s design lends itself to quick notes; I’m sure such a feature could be added, but I doubt it would improve my workflow.