Well don’t you always have to add some modern hardware to link old machines to the internet anyways ? Doesn’t hurt much if “modem” also does some translation of encryption and encoding for supported protocols Gemini, Spartan, Gopher, SFTP etc.
I’d be happy if each old computer could read UTF-8 Gemini pages with just a serial link and a 5$ ESP32 doing the actual TLS connection and eventual filtering or UTF8 to native code page conversion, maybe some light caching.