For many jobs no one requires a certified plumber or electrician or anything.
Where I live (NJ), all electrical work must be done by a licensed electrician — nobody else would simply be issued a permit.
For certain jobs it is a requirement to get a permit, but that is to protect lives.
Yes, sure. The benevolent government bureaucrats in their omniscient wisdom just have higher concern for my life, than I do myself...
In any case, such requirements as the exists, are demanded not by government but by bankers, insurance companies
That would be great, if it were true. It is not. The work must be accepted by the city's employee, who is not personally responsible for it anyway — the installer is. The inspector may — depending on his disposition that day and his general opinion of the house-owner and the installer (their origins, religion, race, personal hygiene) — choose to overlook something fairly important, or make an issue of nothing just to delay the work and the family's moving-in. There is no oversight, no (meaningful) way to appeal, and no alternative.
good recommendations from people who had no expertise in critiquing the actual work
So, you are suggesting, the work of certain professions simply can not be reviewed by the actual consumers — and the sole available fount of the necessary expertise, in your opinion, are the above-mentioned government workers — who do not even have any skin of their own in the game.
And, in a typically Illiberal fashion, you want to impose your opinion on the rest of us — instead of simply allowing people, who are as concerned as you claim to be, to hire independent inspectors — or relying on their insurance companies (or the morgage-holding banks) to hire them (the way they already hire various appraisers). At least, the insurer risks (substantial) money, if your house blows. On the other hand, if the insurer gets overzealous (as numerous building inspectors do), you can switch the insurer. You'll have a choice, in other words — without selling your house and moving to another town.
This was absolutely Uber's right to do, after all the contractors could just leave, but I think it speaks to an issue with capitalistic fantasy.
What "fantasy"? It works exactly the way Capitalism is supposed to — a moment Uber slips-up, various competitors (GetT, Lyft, others) will pick up the disgruntled drivers — many of them are already signed with all of these companies anyway.