I'd say the Game Gear or the PC Engine GT would be better fits than the Nomad for a Switch predecessor
No I think the OP is correct. I think the PC Engine GT had to use wall power, no?
The Nomad is more like the Switch, but back in the 90s, you'd have to carry around like 6 batteries to constantly power this thing and the cartridges were full size Genesis carts, so it was laughably bulky to walk around with.
Also Sega gave this no marketing push or anything at all, they just kinda quietly released it, I don't remember even seeing 1 TV commercial for it ever, even Nintendo pushed the Virtual Boy harder than that.
And of course unlike Switch the Nomad had no new games, just old existing Genesis titles.