I'm not so sure: if you have a well designed workflow, there should be lots of opportunities for mentoring.
Relatedly, I would design a 100% colocated team around basically the same workflow as a 100% distributed team.
Relatedly, I would design a 100% colocated team around basically the same workflow as a 100% distributed team.
Offices may still hold the upper hand here, a lot of people have mental barriers about messaging coworkers vs casually wandering by their office.