There is work like construction, transportation, and customer service that can’t really be remote.
I’m not sure if there’s a good argument for work that can be done remotely to insist on both in person and remote work. It doubles the amount of workstation resources required, or compromises on at least one of them.
Maybe teams benefit from in-person communication? That’s probably simpler for some that haven’t found comparable online versions of whiteboarding tools or whatever. Good tools do exist, but feel people that haven’t adapted to them by now, it’ll take some real demand to make it happen. This might not be a characteristic of a highly effective team, though.
Most frequently, hybrid insistence seems do be more about justifying middle management, based on my highly unscientific observations.