The hardest part for me is balancing slack and video conferences. Slack can be useful but it's hard to have more nuanced conversations and make complex decisions. Those really need conversation to make them effective.
A friend recently mentioned that they are on a forced return to office 3 days a week and they spend most of their day on calls with people in other cities and countries. If I had a job I was mildly disinterested in and was forced to commute for no reason, that would nudge me to quietly apply for other jobs. Any company claiming to be climate friendly and forcing people to commute is hypocritical (cough cough Amazon).
If someone wants to be in an office, then accommodate them. Then for everyone else shift the office space budget to the travel budget. Done.