Yes but sctp can run over udp, that's how I ever used it. And QUIC has bitten the bullet of using udp over the Internet, so it was possible. Just feels like a missed opportunity, but now that QUIC is here, there's not much more to say. There's lots of fancy things with sctp that I always found magic and it defines the base of your architecture. Having a multi-homing, multi-path transport API alleviates many headaches.
If you want your networking software to be widely used, you probably don't want to limit yourself by using sctp.