markdown, html and txt files over microsoft docx.
plain text csv files over excel or g sheets.
markdown, html, odp over pptx presentation files.
yaml or toml for some configuration info.
ffmpeg for basic video/image file editing. (I haven’t used this a lot though).

It’s just not about avoiding vendor dependency.
You can get more info out of these open format files easily with other opensource tools without spending money or computer resources.

Instead of relying on some excel specific formula, you can write a simple bash or awk script to fetch a desired output from the csv.

These files are also easy to work with.
You don’t need a proprietary software to open these. There are opensource editors and programs that allow you to open these.
And these opensource alternatives are blazing fast than their proprietary cousins because they’re lightweight programs.

This is a rabbit hole. But it’s worth pursuing because this will save you a lot of money, headache and time in the long run.

The formats that I haven’t yet explored, but want to:

  • calendar and contact info saved in opensource format that I can manage programmatically
  • sqlite db as a sort of more powerful csv alternative and a quick way to data dump
  • imagemagick and ffmpeg
  • CLI parsers for machine-readable formats like xml, json, yaml (jq)