Secondly, people who have never been managers often don't understand the externalities. As a manager, I've been asked "Why should the devs get so much better computers/bigger screens etc than us?" Different conditions can create an intense feeling of unfairness among people who don't get those conditions. Those types of things can wreck the culture at a company.
Finally, open space is much much more flexible, so easier to change up when you need people to sprint together on a thing, when you need to scale up your team etc. Offices are extremely inflexible and typically anchorpoints for people's perception of their own status. Therefore once someone has an office, it's practically impossible to get them to not have one any more, even if circumstances have significantly changed.
It's easy to blame management but it may well be that management have a totally different set of problems to consider than you.