For example, if I'm part of a club and I think the treasurer is doing a bad job, if there are 'formal' elections I can run for treasurer (or vote for a different treasurer) and make changes.

In a structureless org it is much harder to tell the 'popular people' that, for example, some of the expenses they are having the club reimburse should actually be paid out of pocket (because by definition the 'popular people' have a lot of informal influence - average or unpopular people are much easier to correct).

If one person is highly charismatic they could wield huge amounts of power in a structureless organization - but in a structured organization there can be clear limits on what each role can do. Structures can constrain power and make it easier for those with less informal power to make changes or to create those limits.

Global Changes imply that someone has the power to changes how the whole organization operates, which is the whole point of concentration of power.

If something is that major, then all the participants or factions have to unite on that one thing and then disband.

There is no “club” and there is no single “club account” that a treasurer controls. If there has to be one for purposes of interfacing with others, we have a computer network emulate it to the outside.

Concentration of power can be defined, measured, and opposed in principle. The question is, can any structure prevent it? Every unit of time it has to be more expensive to maintain a faction than to let it disband. And you have to factor in all the possible ways to profit by collusion, that’s what the challenge is.

Consider upvoting comments on HN for example. That there is a microcosm of what we are talkung about. We want each vote to be an honest signal, to detect and punish voting rings. But how? There is a computer program in charge ultimately of various things including banning some accounts.