Some of them (maybe most?) at least require a pre-employment drug test. Some require random drug tests while employed - and some of those will be hair follicle tests - and honestly, I can't understand how smoking weed occasionally will make you bad at taking calls.
Some - if not most - will absolutely expect you to put up with an array of abuse from customers and be nice when it happens. Americans don't require this from police.
And don't get me started on the conditions for telephone sales. I worked in a call center for deliquent phone bills, and heard stories about how much better it was there. I guess phone sales is really soul-crushing.
Truly, the worst part about this is simply that a lot of the folks affected have no realistic safety net.