Can I do something like this on a Raspberry Pi?

Something like Syncthing, but for hosting media would be fantastic. No need to deal with opening ports in the router and all those shenanigans. Something that you install and it just works, without any additional software. Is there anything like this?

This just shows that the whole “muh, it is the corporations fault for the climate emergency, there is nothing I can do about it!” is a load of BS. You can vote with your wallet. Become anti-consumption.