I've actually went far in planning and acquiring gear for my apartment, though it's a low priority task for me.

Turns out there are tons of stuff that sip power (set-up boxes, Ethernet switches, NAS...) that can either be powered directly by Power-over-Ethernet or through a splitter (DC-DC converter). That can be handled by a PoE Ethernet switch, which itself is usually powered at 54VDC, so it's also an excuse to run a homelab on 48VDC and get rid of tons of power supplies.

However, DC isn't well suited for the entire home for several reasons, mostly due to cheapness and historical reasons. For example, AC breakers are dirt cheap because arcs naturally extinguish when current crosses zero volts, whereas DC doesn't.

There are areas where DC is used. I work on telecommunication gear where nearly everything is -48VDC, but the beefy copper busbars needed to push large amounts of power through them would make a homeowner cry at the expense. Higher voltage is possible to compensate, but you enter not-safe-for-touch territory and I'm not knowledgeable about that.