I think that fundamentally, misaligned incentives are probably the greatest category of problems facing groups of people with the problem being more significant and detrimental when societies / organisations / groups are larger. 

How does this problem's size scale with number of humans towards the same aim i'm not 100% sure, but I reckon AT LEAST linearly?

It seems to me that it is obvious there can be no misaligned incentives if there is only one person on earth. Arguably 2 people on earth also no misaligned incentives, assuming that they are equal, as each person's incentive will just be doing what he/she wants. 

The damage that misaligned incentives does is that it is a structural problem that allows non-malicious peoples to do damage to the greater whole naturally i.e just by pursuing their own self interest. This bar of "naturally" is very significant as this is the default state of most peoples. I might, on a very free day, argue that to not act naturally for good (e.g to align to the greater project regardless of the misaligned incentives) requires a deviation that is almost on par in "effort" or "deviation-ness" as to actively, maliciously sabotage something (I suppose that might be an equal if we take moral scruples out of the equation).

Together with stupidity (which allows a person to do damage to the greater whole naturally by incompetence), misaligned incentives probably account for a good portion of the harm done to the greater whole with only largely malicious harm unaccounted for.

Let's give some examples of misaligned incentives:

1. Financial advisors recommend a product that would earn them more commission. The commission aligns their monetary incentives with that of the product owner (which wants more people to invest in the product, presumably because they can earn fees of assets under management). However, this might potentially be out of alignment with the investor's interest, that is... to earn a high return on investment based on risk profile .etc.

2. Politicians vote for policies that gain them the most money. The industry lobbies with gifts and money, monetarily aligning the politicians with them. However, this might potentially be out of alignment with the voter's interest.

3. Managers promote someone more incompetent in their team to be "assistant manager" in order to safeguard their own position from being threatened. However, this might potentially be out  of alignment with the organisation that wants the best person for the job.

I suppose the last example is the classic principal-agent problem though the rest are probably also somewhat.

I recognise that in each scenario there is an implicit should. That financial advisors SHOULD be aligned with the investor's, that politicians SHOULD align with voters (or at least society, if you are not in a democracy), that managers SHOULD align with the organisation which is kinda un-argued for but if you wanna argue about that, maybe pick it up with someone who has the energy to argue that with you cos that's not me.

Insofar as the SHOULD holds, it follows that structures SHOULD seek to align incentives in order to prevent these self-destructive forces from acting against the structures. 

There are many ways to re-align incentives:

1. One could just ban the common misalignment of incentives e.g make bribery (by any other name) illegal. This could be blocking commissions based structures for financial advisors, criminalising lobbying .etc.

2. One could just realign monetarily by paying them better. E.g clients pay more for financial advice, advisor doesn't need to earn money from commission. Same for politicians, same for most govt functions.

3. One could re-align with the correct person / thing more often. This could be perhaps choosing a new financial advisor more often, rotating managers more often, voting for politicians more often (e.g after each time they vote).

Ok sry, quite pathetic, no bandwidth to write more. lolol. too much studying GST and listening to international tax structures. All I wanted to say, really, is that corruption is very bad.