Alternating current is substantially easier to step up/down in voltage, much nicer to anything that modulated current flow and has a lot of convenient aspects for motors. Like for like the DC solution costs just a little bit more every step of the way.

Even if you're not doing long distance transmission the cost of all those things that are worse about DC are going to be bore across the entirety of your economy that uses AC. DC makes sense here because the supply chain is so dysfunctional that making the "better" solution work would actually cost more than the "12v doodads from china" style solution. Eventually as electrification continues the choice of DC will become a drag though.