I like (some aspects of) SCTP too but it's not a solution to this problem.
If you've followed Dave Taht's bufferbloat stuff, the reason he lost faith in TCP is because middle devices have access to the TCP header and can interfere with it.
If SCTP got popular, then middle devices would ruin SCTP in the same way.
QUIC is the bufferbloat preferred solution because the header is encrypted. It's not possible for a middle device to interfere with QUIC. Endpoints, and only endpoints, control their own traffic.
If you've followed Dave Taht's bufferbloat stuff, the reason he lost faith in TCP is because middle devices have access to the TCP header and can interfere with it.
If SCTP got popular, then middle devices would ruin SCTP in the same way.
QUIC is the bufferbloat preferred solution because the header is encrypted. It's not possible for a middle device to interfere with QUIC. Endpoints, and only endpoints, control their own traffic.