CalyxOS is also available for the Fairphone and you don't have to give money to Google.

If I am forced to use word documents, then Onlyoffice.

Otherwise Latex for text and presentation (beamer).
For tables I use the terminal program sc-im, which also works with excel files.

That does the trick, thanks!

I asked a friend for recommendations and he proposed Wintersteel or Mistborn. Since I couldn't get Wintersteel DRM free for my ebook reader, I gave Mistborn I try. Already the prologue had me hooked and within the next 1 1/2 years I read all the Cosmere books.

I managed to sign up just a few min ago. Are you trying to sign up via the beehaw.org website?

It's very difficult to learn, you just need to adapt to the Latex style of writing and Latex takes care of (almost) all the formatting.

peek.nvim should do what you like. I found it however not so straightforward to get it running.

Please share if you find something better which doesn't need a browser.