I'm in a very similar situation like you are. I too have started to be annoyed with the Big Tech products and the Internet in general.
I have switched to Lemmy, shut down my gmail account and opened a Proton Mail, and switched from using Google search engine to Qwant.
I too have switched to Linux Mint, and I'm loving it. TBH my IT colleauges talked me into buying refurbished Thinkpad laptop and told me to install Linux Mint. Boy am I glad I did that.
The next step for me is switching to Fairphone :D
In my case the main reason is... removable battery.
This fair thing sounds like a gimmick to me too