> Unless you live close to the office, you're probably looking at least an hour on either side of your day commutting

That's a choice though. I just lived where I worked. I can see the argument when you're talking about low-paid work, but if you are a software engineer, you can probably afford to not spend an hour commuting.

> going to the office pretty much sucks.

This is a highly personal thing though. For me, having children home in the afternoon drastically dampens my productivity, and the benefits from being there extend to greater awareness of what other people are working on, and decreased perceived barrier to collaboration. When you see another developer in the kitchen just sipping coffee or waiting for an elevator, you don't feel like you're interrupting to ask him how he got past a certain issue, or in telling him about a new tool that you just tried. You can post those thoughts in a public channel! But the person who "needs" to see it might not see it, and sending a DM is kind of a demand such that many people won't do it unless absolutely necessary.

Text is for many people just not superior to communicating in person. Slack is a simulacrum of in-person communication, not the platonic ideal.