And in the US a new worker can only join the healthcare plan during certain times of year! New workers often have to wait months with a health insurance gap before they can get on the new plan.
That's up to the new employer. Federal law only requires special enrollment within 90 days of hire. So technically there can be up to a 3 month gap.
In practice, that is very rare. Usually new coverage becomes effective on the hire date.
Workers changing jobs often just elect for COBRA or selecting a temporary subsidized ACA plan to bridge the gap though. Nobody is really forced to go without coverage.
I am not an expert but I am pretty sure changing a job is a "qualified life event" that allows an out-of-band change. I hate privatized insurance but I didn't think this thing in particular was a problem.
That is incorrect. When you start a new job you have a few weeks to enroll.
However, you sometimes have to wait for the plan to begin coverage. Something like "after 30 days of employment", or "on the first day of the first full month of employment". These are indeed idiotic limitations.
Worst case scenario, if you are changing job and something really bad happens during these 2 weeks where you don't have coverage you can retroactively enroll in COBRA.