Whatever your body plan, I suspect higher order intelligence is a sort of snowball effect from having dexterous appendages you can use while walking and making noises at the same time.

Without that trio it may just be too difficult to keep going up the ladder to tool user and sentience.

That doesn’t eliminate crab people. It may not eliminate cephalopods. It may eliminate sea mammals without external help (David Brin gives dolphins prosthetic arms via human assistance).

It may also be that we need combustion to advance, or that may be only a problem on planets with our parameters.