and firing people is also not a mystery, interestingly PIPs are a US invention (but if labor laws are so lax, why were they needed there? :))
In reality what happens is you get 3 months notice of a firing in the form of PIP. Perhaps if you work at Walmart you can get fired on the spot, but honestly in industries where this is a common occupance, it's also well known that the employees also just don't give any notice at all either. They just stop showing up, maybe won't even give a 1 second of notice.
Personally, I'm happy for at will as someone who has had a shitty. Shitty job that ate at my mental health. I just had to say "today is my last day" and I fucking left and that was that. Got a final pay check and paperwork for continuing my benefits if I wanted them and this was at a random company in a labor hostile state. In some place like California, they would have been required to pay my last paycheck that moment instead of when the never payment day was.
I've seen employees work contacts that mandate notices by punishing you with legally enforced fines and whatnot and I just cannot see the benefit of being forced to give notice. It's just encourages your employer to make your life hell in that period if you're on bad terms and you had a good reason for leaving.
Right to work laws can get bent though. That's active underminement of unions for no benefit at all for an employee.
Granted, the hoarding of money and drive to greater wealth eventually leads to a capitalistic dystopias with massive wealth inequality. But you get lots of startups!