And I don't think a quarterly on-site is enough.
If it were that good, software engineering in the US would suffer the same fate as manufacturing: it would disappear to cheaper foreign workers and only specialties would survive.
Would it be? Seems like, at a minimum, various employer liabilities that exist when an employee is working independently of whether or not it is at the employer’s location become less controlled in remote work, which potentially works strongly against that.
Also, the argument you make, even in the best case, fails to grasp the difference between “is” and “has always been” and the magnitude of impact of cultural inertia in favor of what has worked well in the past.
Also, I think the size of the company plays an important role as well. We're about 2000 employees in the IT departments alone, I somehow cannot imagine all of those people permanently working from home while also being able to properly cooperate with the other 100k employees.
They could also get an exception and attend the working sessions remotely. But there's a chance that could lead to fewer opportunities for advancement for them, because they weren't there. Which sucks. It's not an ideal situation.
BTW, lots of enterprise sales companies already do annual "sales kickoff" events where they fly all their salespeople globally to a single place. It's not unprecedented.
You're not far off the description of parents of young and early school-age children. Kids are in school/daycare for part of the day, then at home, needing dinner, care, etc.
Salespeople know, when they take their job, that they'll be expected to travel for work. Developers may not expect that to be a requirement of their job.
There was a difference in amount of time wasted though. Going to the office is in my case much more wasteful, mostly due to travel time (90 minutes per day).