it's ironic how the worst piece of proprietary software made to trick customers is in the printers, the software straight up just lies on there being no ink
The real issue is precision accuracy. Keeping things to 2D might sound easier than 3D, but 3D printers don't need the level of accuracy and precision that 2D printers do. 300dpi means dots every 85 microns. A very carefully tuned FDM 3D printer can get around 50 microns, but see below for the gory details:
Either way, 300dpi isn't particularly impressive for a paper printer. Usable, but there's going to be some blockiness to text, and graphics won't be good at all. 600 or 1200dpi is more like it. Which means we take that 85 microns and cut it in half, and maybe cut it in half again.
If we're talking color, than our difficulty increases 4x (because there's four cartridges for CMYK). They all have to be aligned properly to mix the colors to get a good image. We're also definitely headed towards 1200dpi at a minimum for good results.
Now, an open source plotter would be interesting. Not great for text documents, but useful for diagrams.
Printers are a restricted item in most countries when it comes to manufacturing and producing due to counterfeiting, as such any open source printer you could produce would most likely run a foul of local laws due to the ability to remove anti-counterfeiting requirements.
A lot of places like this don't want you using your own devices inside. I'd guess that they've disabled the cameras, or at least made it difficult to send photos outside of the device?
I actually had to look this up. You mentioned wework in Edinburgh and compare it to a gay sauna in Glasgow. Have you factored in the commuting time between going from Glasgow to Edinburgh park?