I work at a tech-adjacent company with no middle management and no, it sucks even more. The work doesn't disappear, it simply gets divided and spread out over a lot more people, many of those with no real executive power. I don't even think this saves my employer any money in the long run.

The manager role is inevitable once scale reaches certain thresholds.

Yeah. There's always such a lack of realpolitik in these discussions. They turn into endless bike shedding about what a manager is supposed to do according to some ideology of management, rather than the reality of the decisions managers are actually in control of and their actual tangible outputs.