There’s a huge difference between a few times a year and once every 1-2 weeks, both on the company and the employee. At once a quarter we can just rent a coworking space and fly in, but at once a week everyone needs to live within ~90min of the office and the company needs to maintain some level of excess office capacity in order to seat these workers 1x a week.
To my eye remote 4x a week forfeits most of the benefits of full remote purely for the sake of a vestigial habit. It seems superior to me that either the team either goes full remote, or reverts to a “remote work when errands require it” arrangement.
I don't necessarily disagree and, in fact, you're describing the way that my broader group is organized albeit with some subset of people normally going into an office.
That said, there are plenty of people who want to go into an office semi-regularly and, if you tell them they're going to be 100% remote--even if financial arrangements are made to subsidize a co-working space in some manner--they're probably not going to like it and will probably leave for a more office-friendly company.
To my eye remote 4x a week forfeits most of the benefits of full remote purely for the sake of a vestigial habit. It seems superior to me that either the team either goes full remote, or reverts to a “remote work when errands require it” arrangement.