There is definitely a lack of trust going on in a lot of places. There is also the question of building relationships. Ask any sales person if he/she thinks warming up a relationship is easier face-to-face or from a distance.

Then there is the fact that not everyone is efficient with WFH.

Finally, if one manages to split his tasks in batches WFH/office hybrid could definitely become an option for many, e.g. work with team in office one week / work on long form client emails remotely. But that's a very big IF.