It matters to me that my digital data (PII or not) is not tracked aimlessly and sold to 3rd parties without my consent. So,
I use a VPN because I don't trust my ISP.
I use LineageOS with microG because I don't trust the phone manufacturer and Google to not track me.
I use Linux coz fuck Windows. Hardened with secureboot and FDE with TPM.
I use ungoogled chromium with uBlock and NoScript.
I also selfhost most of the services that I can replace with FOSS alternatives. Can be a PITA maintaining them at times but I sleep happy at night knowing my data is not on some Google(-like) farm. E.g For Youtube I do make use of public invidious instances etc.
Any app (on phone and PC) that doesn't need internet permissions (or any other unnecessary permissions) has them toggled off. Flatpaks and flatseal makes this so easy on Linux.
Any social media app that works well as a PWA is not installed. And if needed on my phone, it's installed into the secondary work profile where it can't read my files/contacts/etc.
All data I consider private is encrypted at-rest. Same is routinely backed up to different cloud storage providers.
Any account that I consider important has 2FA behind it. Most accounts I just use disposable emails to register.
Ads are all effectively blocked on the devices I use courtesy of dns filtering.