Switch, easily. I think PS5 will be harder to get for sure, but Switch is in its 4th holiday season and has a tonne of momentum and a whole lot more stock. Switch definitely.
My Console Library:
PS5, Switch, XSX
PS4, PS3, PS2, PS1, WiiU, Wii, GCN, N64 SNES, XBO, 360
3DS, DS, GBA, Vita, PSP, Android