Half your bus friends you only knew by first name. They still made the ride shorter.

Not every useful relationship needs depth. There are people you talk to for twenty minutes a day for three years and never learn a surname, and the twenty minutes were still better for them being there. Low-stakes company does real work: it fills dead time and keeps a morning from being endurance. Calling that shallow misses what it was for.

Count the people you see regularly and know only slightly, then be slightly better to one of them. Ask what their weekend was. You are not building a friendship on a deadline, only making the next ride shorter for both of you.