This is very important.
For those who use a laptop outside office desks, there is a lot of difference between flimsy setups with dongles hanging on wires, and the mechanically solid laptop case. Much easier to carry it around in one piece.
If you need something more 'rigid', things like this exist: https://smile.amazon.com/dp/product/B07PCP5J4Z
In the case of the framework laptop, most of the "modules" just seem to be USBC/Thunderbolt-to-X dongles that fit flush with the case.