Whether we are preparing undergraduates for research in industry or academia effective collaboration is an important higher skill. I think there are two aspects to this in mathematics - thinking together about problems and working, where the latter often allows differentiation of roles.
In subjects such as engineering it can be clearer how one might set up group projects which model how research happens in this field. How can we incorporate this into a course which is very heavy on individual ability to understand and apply proof techniques to the exclusion of most other skills (such as undergraduate mathematics degrees in the UK, where students study maths specifically and are able to specialise into pure/applied/etc. in the second or third year)?
Some students will study together and some will not, while this is not discouraged can it be encouraged or made into a formal objective? Does studying together on lecture notes or individual problem sheets actually teach collaborative problem-solving, or would it be better to design specific tasks or resources to encourage group work?