[phh]

For the "EC" of ECMP and for the "TCP" of MPTCP. I'm only half-joking:

MPTCP works just fine on different internet connections, while ECMP assumes everything has the same bandwidth. And the MPTCP gives the reliability of TCP: if one connection is dead, it'll detect it and transmit lost packets to the other one. It even supports break-before-make, so you can loose all your internet connections, then get a new one, and it'll resume.