Why? Because if you check the CVs of most of Politburo members they have degrees in science and engineering. QED!
Maybe because modern American mainstream culture has people worshiping the "clever" conman who got rich quick by gaming the system and scamming others, as opposed to hard working nerd who put in the long time and effort for an honest enrichment.
Democratic societies get the leaders they deserve as they are a mirror of the people themselves.
The fact that people vote at all.
Running for office is a risky endeavour: you have to take time off from your job to actually run, with a decent chance of not winning. How many employers would be willing to give you a leave of absence to do this? Further, if you happen to lose your seat you are now unemployed: who is going to hire someone who has not been in the field for x years?
Law is probably one field where one can hop in and out easily, so it's why we have so many lawyers go into politics: the practice of the field doesn't change too quickly, so one can always join a firm. Similarly if you are a "businessman" you can give yourself time off from your own business (let someone else manage/CEO) since you're the boss.
Whereas in an engineering or technical field, you basically have to end your career in it. Or you perhaps stop being a day-to-day participant and go into a more generic 'management' role where it is easier to hop around companies in case you need to enter/leave politics depending on how many votes go your way.
Whereas in the CCP, (AIUI) you basically go into the 'management track' and get appointed to various positions with-in the party. You never "leave" your career as you move up the party leadership chain.
Only in USA, the rest of the world doesn't see lawyers flock to politics. It seems more like there is some corruption that makes lawyers mingle so much with politicians and they scratch each others backs, otherwise why would it be so much more lawyers in politics in USA than any other country?
People hate lawyers, they wouldn't vote on them if they didn't have to, but when the parties mostly show you lawyers to vote for then people don't have much of a choice. In the rest of the world were they do have that choice lawyers doesn't get voted in that much.
This is one factor that explains why lawyers take so many vacations and seem so generally relaxed.
One metric:
* https://en.wikipedia.org/wiki/The_Economist_Democracy_Index
Don't confuse things being soiled by capitalism as democracy somehow is the bad part. There are plenty of examples of democracies that haven't succumbed to capitalism as badly as the US has.
Capitalism is bad sure, but so far it's the least bad system we ever had and the US is one of the least bad implementations. Capitalism got a lot of countries out of extreme poverty.
Look at South Korea if you want to see true dystopian capitalism.
See section Change from Charismatic Revolutionaries to Technocrats especially bullet points four and five in this link on Chinese leadership: https://factsanddetails.com/china/cat8/4sub1/item2247.html.
