Also, you can pick up on the body language of people. When I want to discuss something with one of my colleagues, I can glance over at their desk and see if they're focused on something or just staring out of the window, waiting for something to compile. That way I don't have to rip him out of his focus like I would usually have to do with Slack etc.

I'm remote, and have largely fixed the Slack issue by keeping it silent on my desktop - no notifications. I have a very small set of filters for notification on my iPad, like if someone mentions me by name or certain people DM me. Otherwise, I tab over to Slack when I'm waiting for something else.

I agree with all your points.

But consider the costs of that colocated time. 3 hours out of a worker's day is a lot - they could either do more work (boo) or be less stressed while they work (yay) without that commute. They'd also have fewer sick days (colds don't do TCP).

And the flip side of serendipitous conversations is distracting chatter. Which one affects productivity more?

Oh yeah, and office space costs a lot.

Remote work isn't all roses. But colocation is extremely expensive. The question is whether it's worth it.

Yes if everyone were commuting 3 hours then that would tilt the scales toward telecommuting in a big way.

But 3 hrs daily commute time is still an outlier, even in the Bay Area. Especially since many major companies have shuttles that allow people to use their commute time productively.