I personally use #logseq for note taking and #libreoffice for more complex documents in the open document format.

I have not yet tested but read good reviews about #onlyoffice which offers collaboration.

That are the two supported by https://www.privacyguides.org/en/office-suites/#criteria I use mostly for checking private alternatives.

I think it is great to use free software, which supports the open document format for fancy documents and a very basic Markdown syntax for note taking. Like this files are most likely to be useful in the future.