I think it depends on what kind of old "ten speed" you get though. There were bikes designed for touring, commuting, and then there were bikes for racing. And each manufacturer kinda did their own thing too.

An example of extreme weirdness would be the entry and mid level Schwinn 10 speeds from the 60s and 70s. Simple commuter bikes. They have unnecessarily and ridiculously high bottom brackets. Maybe it was overly cautious designing to reduce pedal strike. BB drop is like ~50mms. With the big wheels and tires those things came with, striking a pedal was rare.