You are very mistaken. Having scans doesn't do all the work for you, at best you get a mesh you have to retopologize, in most cases you can only use the mesh for reference. They probably couldn't scan most props anyways and could only go off reference photos, which is pretty standard. Besides that, setting up the materials these days to be physically based is going to be more work than before. Then there's stuff like the environments which are way more complex as well which require a lot of work and there's nothing even to scan for that.
Then there's stuff like animation systems which have come a long way with how things are blended together along with using physics systems integrated with pre-made animations to get things more realistic.
Many games certainly could be done with a smaller team if they weren't under some kind of big corporate control, but it's not a case that any game these days could be done with 20 people if there wasn't a problem like that. Things get more complex over time, it's as simple as that.
Then there's stuff like animation systems which have come a long way with how things are blended together along with using physics systems integrated with pre-made animations to get things more realistic.
Many games certainly could be done with a smaller team if they weren't under some kind of big corporate control, but it's not a case that any game these days could be done with 20 people if there wasn't a problem like that. Things get more complex over time, it's as simple as that.