TIL Safari seems to have some basic HTTPS Everywhere-like functionality, disabled by default
For the unaware, HTTPS Everywhere is a browser extension not available for Safari that uses a whitelist of sites to attempt to encrypt as many of your connections as possible with HTTPS.
In macOS you can enable it by enabling the Develop menu (Preferences > Advanced > Show Develop menu in menu bar) then enabling the option in Develop > Experimental Features > Automatic HTTPS upgrade.
In iOS you can enable it by going to Settings > Safari > Advanced > Experimental Features > Automatic HTTPS upgrade.
I have no idea how effective this is compared to HTTPS Everywhere or even if it works at all (I’m not exactly sure how to test it, as most websites today automatically redirect you to HTTPS anyway), but the option’s there. I believe it was added in macOS Catalina and iOS 13, as I don’t remember seeing it before (but that’s a complete guess).