I don't really get how this question pertains to F-droid specifically.
But, in networks that are more locked down, they can use stuff like deep packet inspection to figure out what traffic is happening, and automatically block it. Socks is a protocol explicitly for proxying, and runs over TCP. Depending on the setup, deep packet inspection can catch it.
On the other hand, disguising traffic as HTTP/HTTPS makes it very, very hard to detect that someone is doing something other than visiting an innocuous website.
At the high school I went to, they had Deep Packet Inspection set up to such a level that they could automatically detect and block VPN connections. Wireguard and OpenVPN would be caught basically instantly, and then you would be kicked off of the internet for 10 minutes. Although very extreme, a "10 minutes no internet" punishment is nothing in comparison to prison time or any number of extreme punishments authoritarian countries can come up with.
To get around the school firewall, I set up a web proxy called Metallic: https://github.com/cognetwork-dev/Metallic/ . This is basically a website, that lets me access other websites from within that website, and it's very, very difficult to block because of that nature.