While this is HN, with its associated demographics, the reality is that many office jobs just aren't as feasible for remote work. Face time and hallway conversations can be incredibly important for a healthy company.
Also can you say what type of content can only be communicated in a hallway but not via video conferencing, chat, phone or email?
For example, my job is to write software for 40' display walls and immersion rooms that are controlled by input devices connected to (very) pricey room-sized spatial tracking systems. Sometimes I'm able to do my work for the day remotely or otherwise without access to these systems, but quite often an engineer or designer has to be sitting in the space to properly develop, test, or debug an application written for it.
Landlines could solve some of those problems, but how often are all parties going to have landlines?
Some of the most important information I've picked up at work has been from overhearing keywords and jumping into a conversation across the room, chatting with coworkers at lunch, etc.
I could do something that resembles my software engineering job if I only worked on the tickets as written and the Zoom meetings as scheduled, but not nearly as well.
I currently rely on wifi calling on my cell phone and it works flawlessly. I also rely on Vidyo, Skype and Google Hangouts. All of the latest versions of these work just fine. There are many distributed teams that use these to great effect every day, mine included.
>"Some of the most important information I've picked up at work has been from overhearing keywords and jumping into a conversation across the room, chatting with coworkers at lunch, etc."
You could also miss out on these if you happened to be in the bathroom or getting a coffee at that time, or wearing headphones. "Being within ear shot" seems like a strange requirement in 2017.
Here's another angle. What about HR? Marketing? Those are very people-focused professions that typically involve lots of in-person conversations. I'm a digital marketer myself, and while yes, the job can technically be done remotely, I'd say that about half of what I do couldn't be done to the level I do it at without in-person interactions or those quick hallway conversations. And that is despite working at a very remote-friendly company where we're all on Slack.
Also, your question about what type of content can only be communicated in a hallway comes across as very black and white. Sure, technically most of that communication could occur through one of those other options. But you know what? It won't be as effective for some of the other reasons people noted. You and your personal experiences might be outliers, but for most people there is a BIG difference between having a sensitive conversation with someone in a closed door meeting and having it be done remotely. For example--let's say someone is being let go. It always sucks, but having the HR person or your manager sitting you down and looking you in the eye while it happens would probably make you feel a lot less crappy about the situation than if the HR person dialed into a hangout, and mid-sentence the connection stuttered, or their video wasn't working.
Despite creating everything digitally, there's a lot of high-quality photographic printing to be pinned up and observed during critiques with senior people.
A team will also crowd around someone at their desk and discuss, point out, live model/design something.
The level of equipment ($4k+ desktop towers) wouldn't be as easy to standardize or support. If a user ran into an issue, one in which remoting in wouldn't work for support, it'd take much more time to diagnose and rectify rather than on-site. They are definitely not as computer savvy as probably a lot of the folks working at GitHub but need high-performance machines.
We have a client representative that flies in from a city a couple hours away every week to go over designs. They sit in a large conference room with a team and has a remote conference with team members in the city they flew in from.
Any pre series-C company, which is still adjusting the product/market fit and fighting for survival will not be able to afford the lack of creativity that a core local engineering team provides, and the higher communication costs associated to working remotely (especially in different time-zones).
It maybe can work for non-core engineers, or for remote core-engineers that have given up to their chances to build up a career and level up, since those spots will be taken by folks who work locally next to the leadership team.
Most likely if a remote engineer turns out to be spectacular, he will receive an offer to move locally under the same roof in order to unlock his career.
Here is a nice list of companies that proves your assertion wrong. Note many of these started as "remote only":