Every Day austronaut did show though that even theoretical aerospike engines are not a good choice if you don't go single stage to orbit, and even with aerospike engines, an SSTO is worse than a multi-stage rocket, especially if it can be (partially) reused like the falcon.

The added weight of every aero spike engine ever made obviated its performance benefits, even for SSTO. SpaceX has always focused on super high thrust to weight ratio engines (Merlin and Raptor) and that (along with lighter tanks) has more than offset the lower ISP of their propellants.