I created a google takeout and in that zip file I found some files containing a ton of data about me. It has logged every single page I visited while using the google search engine and chrome browser. It even logged every single time I opened an app on my old android phone. It even has VOICE RECORDINGS of me and a log of every time I used google assistant. This is just some of the data and I’m very sure there is even more data they have.
Toss Linux Mint on a bootable USB, fire up a live version and play around a bit. I was in the same boat and am working on fully transitioning over. The only minor hurdles are Office 365 and other Windows-only programs, but there are ways to get those to work, or just run a Windows VM.