My own use for OneNote was mainly drawing/hand written notes using a drawing tablet. For that use case, I have replaced it with Xournal++
For other notes written with the keyboard, I use simple local markdown files.
All my notes are synced between computers with Syncthing
Funnily enough, the CEO of PostNord Denmark also earns ~700k, but DKK, so that is around 1.5 time that, but for running the part of the company with more losses
Source (p. 23)