I just tried the Am I Unique site and I’m surprised by the amount of information the sites can have. Why do they know if I’m connected using 4G or 5G for example? Even using a privacy browser

They should stop trying

For banking, I use the website instead of the application. I have very few non-open-source applications left on my phone.

Use cash. A card payment allows your bank and the shop to track you.

A few years ago, I’ve read an article where the journalists investigated this. They asked to Facebook it they actually do it and Facebook confirmed.