I work at a company that is strict about not allowing developers to work remotely except in rare circumstances (i.e. an employee wanted to spend time in another state to be with their family for a few weeks, and they wanted to work during most of that time rather than take vacation).

For us, it's about keeping the barriers to communication as low as possible. We do pair programming, so we're already very much oriented to frequent communication. While tools like Slack and email get the job done if your team is working remotely, nothing beats being able to turn around in your chair and quickly engage another pair of developers (or the entire dev team if necessary) in a quick discussion about something. This extends to the rest of the team (designers, product managers, relevant business analysts, etc). At any point I can walk 30 steps or less and talk to anyone from the product or business teams about requirements.

Admittedly we keep strict working hours to maximize the amount of time the team is together (8am to 5pm, everyone takes the same lunch hour). The flip side of those strict hours is that we are never asked to work overtime or weekends. We come in, the entire team works for 8 hours together, and then we go home. People never believe me until they see it in person, but our office will be buzzing with work at 4:58, and then be a ghost town at 5:02... unless we decide to play some post-work ping pong or grab a beer!

I'm not saying that I don't think that remote work can be effective, because I've seen it work. But I think it's disingenuous to say that remote work is equivalent to colocation. The best argument I've seen for seeking remote workers is when a company is located in an undesirable city and struggles to attract talent (i.e. a company in Paducah, Kentucky will struggle to attract candidates in a way that a company in Denver, Colorado probably will not).