Time spent on certain activities is more beneficial than time spent on others. The best example is the difference between a proactive team/committee member versus a lazy one who is there to, well, put in their time.
Some people are more inept, less intellectual and emotionally equipped than others.
Basically, there is a problem of equivalence in your proposed system that I don't think is possible to resolve. But of course, there's also the inevitable advantages offered by such concrete rules for ascension. There are no shortcuts...at the minimum you need to "show up" for, most probably, an inordinate amount of time to be any one of importance in the political sphere.
The ramifications of that might be numerous and worth examining from a theoretical standpoint. Money is stripped of its influence in such a concrete system. That's the biggest positive I can pin down... perhaps your point in the OP?
It seems as if you are inspired by grinding a la video games, which is such a simplistic system compared to leveling up in "life."