All my browsers are configured to ONLY allow https and will flag and ask for an exception if something trys to ping me with http only. I rarely allow an http connection and IF I do so it would only be in a VM. Regarding TLS you might still have a website try and use 1.0, which is majorly obsolete and basically worthless for security. You can manually configure FF to allow 1.0 BUT I would advise against it.
Same here, I hardly ever stumble upon a webpage, which requires port 80, it is mostly used only for downloads these days, sadly even for windows updates.
There are websites with HTTPS/HTTP errors. Try clicking with your mouse on "Area Personale" (Top right corner) of this website: https://www.iliad.it/ This website is really written with feet.....
It works fine for me, no errors and it does not even try to connect to http. It also uses the best certificate by DigiCert.
Uhm......I have this error with both FF + Edge. Maybe it happens because I have a registered account. https://ibb.co/ThxqjtY
No problem on Brave or LibreWolf. It might be caused by adguard or ublock? But yes, when you login, it might invoke an image and some images are still stored on http.
It is not an adblocker problem. If I continue with non-secure HTTP,I get to the login web page,but still HTTPS.