Yeah I was going to mention this. I presume since no OSes natively support SCTP out of the box they just emulate it on top of UDP.
Interestingly, Emscripten emulates UDP by using SCTP's unreliable data packet mode with max retransmission set to zero. Relatedly, there is an excellent library for game networking called enet, which implements reliable and unreliable transmission. Enet is included in Emscripten.
So if you use Enet in emscripten you have: Enet, which uses UDP, which is emulated via SCTP, which is transported via UDP! It's pretty crazy but it actually works well.
Interestingly, Emscripten emulates UDP by using SCTP's unreliable data packet mode with max retransmission set to zero. Relatedly, there is an excellent library for game networking called enet, which implements reliable and unreliable transmission. Enet is included in Emscripten.
So if you use Enet in emscripten you have: Enet, which uses UDP, which is emulated via SCTP, which is transported via UDP! It's pretty crazy but it actually works well.