I absolutely hate useless management layers and unnecessary ceremonies but I've been on teams with no hierarchy and it was Lord of the fly until the most power hungry developers became the effective lead/manager.
Nature abhors a vacuum (c) We are social animals and there is no such thing as "all people are equal" or "flat organization". There is always a structure, only it can be explicit and regulated (and usually more efficient and easy to navigate due to explicit rules), or it can be implicit (aka Wild West).
I’ve been in the startup scenario where the most power-hungry developers successfully rebelled against the CTO and had him resign; “Lord of the Flies” is exactly how I described the maturity-vacuum period that followed.
I was on such team too. There was cycle of power hungry leader, revolution, everyone for himself which special kind of dysfunction, someone else takes power again, revolution, everyone for himself which special kind of dysfunction, ... .
