It looks like the core problem here is all-or-nothing thinking. On projects requiring a lot of creative thinking and multiple disciplines I like a small team all in one room working side-by-side. On projects not requiring much creative thinking but a lot of deep programming I like to be left alone. When I'm working on my business, I enjoy being in a coworking environment.
Instead what gets implemented is these cafeteria-sized cattle rooms where you can't hear yourself think. Or everybody working in silos by themselves -- which over time destroys productivity, oddly enouh.
It's the one-size-fits-all thinking that's the problem here, not the office furniture layout.
How could we show management how is it to use IRC, mailing lists or something like Github to collaborate?
I wish I knew the answer. My gut says to take someone experienced working with remote teams to run a trial, to show them the little tricks that can help make it a success. Quantifying success is often difficult even if we feel we know instinctively if it's working for us, or could be part time or with some changes.
However, I've only worked for companies who had a negative attitude towards working remotely even if they half-heartedly tried it occasionally, or companies who were setup as remote-first. Traversing the gap seems to be hard.
Sorry. I'd love to have a better answer, but I've been around a while and I'm not seeing one yet.
I don't mind going to an open office occasionally if 90% of my week is working from my own office with walls, a chair setup for me and some IT equipment that's actually had some investment.