> There obviously is an advantage to in-person collaboration. There obviously is an advantage to building relationships with co-workers. There obviously is an advantage to letting a junior hire shadow you in person.

Is any of that “obvious”? It goes against everything I’ve seen in my career. The least productive people are those that “build relationships” in the office. The most productive are those who crank out code from home with little to no fuss. I’ve also seen juniors excel remotely because they have the space to research whatever they need and in a remote environment, often feel more comfortable reaching out to senior people for help than the would irl.