90% of the times I'm using phone:
I'm just writing it in messenger, with those bubbles its the most convenient for opening while using other apps. with just private groups with my alt account.
I tried using app "1Sec Note" it shows the text as sticky note over opened app - very convenient. (idk the exact reason but I didn't stick with it for long) tho still having it for rare cases when I have to copy paste for forms.
on PC I either open http://m.me/ or write it to git repo for notes if its related to programming
and after messenger, if its important I write it to Jira (but I cant say much for it, I started using it recently) so far 0 complains besides a that its not open source(but I can export data and migrate to files I hope) and bloated for my needs)
for messenger / using instant messaging platform for notes, the thing that you may not like, but for me it's that can't edit old ones. but I look at it as continuous log of text stream.
"few minutes"?
No, it's literally gone in 30 or sometimes 5 seconds.