It's because of all the idiotic "living wage" stupidity. We will never have a skilled workforce if we don't stop meddling with artificial pay, and cut most welfare programs. Used to be, to make more money, you had to better yourself - which was good for the you and the country. In today's "idiocracy" world, we give people incentives to NOT improve themselves.
I have NO IDEA why this is so hard for so many people to understand.
Because it's pure, unmitigated bullshit.
Learn some economics. I'm not going to give you the full remedial education in this matter in a short post, from Adam Smith through John Maynard Keynes, stopping by the theory of public goods and the theory of externalities, but frankly, you don't know the first thing about what you're talking about. Idiocracy indeed; you're a good example of it.
The actual reasons why it's difficult to find good employees are as old as the dawn of time; you can find complaints about it back to the time of the Pharoahs.
Most people are simply not very competent, and practically nobody is born competent. A lot of them can be
trained to be competent, with effort. Very few companies nowadays take the time to train them -- companies imagine that they can hire fully competent people out of nothing, which is lunacy. Internal training is the only way to get competent employees reliably. You can't expect people to spend money they don't have and time they don't have teaching themselves skills... (not unless they have some sort of welfare system!)
And then there are always some people, like Donald Trump, who have no work ethic, and they will never have a work ethic, regardless of your economic system -- honestly I'd rather put them on a low-rate welfare and keep them out of my hair than have them "working" lazily and gumming up the system. They're going to spend their time goofing off, trying to run scams, or drinking regardless of whether they have a job, but if they have a job, they can do damage by not doing their job. This is a small minority of people.
In Tesla's case, they've hired some lazy deadwood who have to be removed -- which always happens any time you hire people -- these are the MIA delivery specialists.
But MOSTLY Tesla's problem is that they haven't provided proper training and management support. Most of the people at the call center are eager beavers, but they haven't been given the information they need in order to direct your call properly. This is an *upper management* failure.