Since others starting intercepting and eavesdrop on non-authenticated traffic, it got a lot less comfy to do so though. It's not like people are adding encryption to stuff for the fun of it.
it seems the parent comment isn't referring directly to encryption / TLS, but building everything on top of HTTP / HTTPS, which seems to be the default abstraction these days to build on top of.
it's not impossible to implement encryption elsewhere, gemini pretty famously requires it