Mildly joking since there are really no proven facts (other than the population growth decline), but I find reasons to think that we are headed towards more like one of those population attrition futures in which due to

1.- The lack of "new people" to occupy the lower ranks because there is less people born,
2.- Longer lifespans that will cause upper job positions to be almost a lifetime thing, resulting in lack of reward or motivation to most,
3.- Widespread implementation of education, further reducing the separation between people for the different jobs...
4.- Media and entertainment will be better than ever, causing people to loose interest in their real needs (Rome rings a bell?).

The above will lead to a population that, instead of revolting like in the old days, will get depressed (not having offspring, suicide, reclusion, substance abuse, alcohol, etc...) since we are now in a non-violence era, further decreasing the population growth rate down to a population shrinkage until we are down to only the bare minimum to maintain society up and replacing simpler jobs entirely by machines (since there won't be people to do it, but society will still demand their products) which in turn will further the attrition process until humanity is only a small portion of what it is today.

Less people walking around, more robots serving you coffee... then things will become stable for a while until the next aftermath: Robot Rebellion!
This is something William Gibson would love to write about...

Pick the leaders at random with no option to stepdown, and severely punish underperformers by democratic voting.

Pickable people will have to prepare themselves for the task and every aspect of it well or they will suffer!. Additionally, being picked does not get them any tangible benefit or money during the tenure, only until the end without being punished, and they loose it all if punished.

Pros .- Increased voting (everyone wants to cause other people pain)
Cons .- nobody will want the job, but in all honesty, everyone wants to be president because the benefit / investment ratio is close to infinite...