Software is impacted by established userbase, there's just no way a fledgling 20m+ base can compete with a more mature and peaking 70m+ one.It ain't coming close to it's software total. PS4's WW software sales in 2018 were miles ahead of the switch. 2019 i can't see it closing the gap.
If you want to compare software you should really do it aligned although I don't know if we have those figures?