You can use https://github.com/paullouisageneau/libdatachannel for your C/C++ integration needs. It's 10k lines. So the answer is 0. Its required dependencies (I assume this as they are git submodules in deps) are more than 100k lines, though, srtp support making the bulk of it. On my machine it took 11 seconds to compile it.
Irssi is 64k lines (plus its dependencies), so I guess that makes WebRTC complicated.
Can't argue that DCC isn't simple, but perhaps the protocol deviced decades ago is a bit too simple.
Each protocol serves a purpose - it's ORIGINAL purpose. To extend it like this means to degrade it's original usefulness, make it complicated to create new implementations and it won't even compete with a new protocol specifically designed for the new purpose. All this leads to "extinguish" phase.
IRC was implemented in probably hundreds of programs (many/most from scratch, not by importing the same library!). There's even an implementation for Arduino! It's a successful protocol as it is now. Could you run it on Arduino if it had WebRTC in it?
Probably not, but is it worth starting new projects with 16-bit MCUs in the year 2024? 32-bit MCUs are cheap and plentiful in offering.
I realize the IRC protocol is easy to implement (though the protocol itself has flaws that make it difficult e.g. to identify which message is a response to your query, IRC3 addresses this) and I too have done it in the past, but I see zero reasons to embrace it today.
Irssi is 64k lines (plus its dependencies), so I guess that makes WebRTC complicated.
Can't argue that DCC isn't simple, but perhaps the protocol deviced decades ago is a bit too simple.