(This pertains to things as they are in the US. Also just speaking generally, obviously there are exceptions)
With hourly jobs, you work your hourly rate up until the full-time 40hrs/wk. And then, your employer is (usually) required to pay you overtime at 1.5x your normal wage.
In demanding mid-upper level salaried jobs, you're not paid by the amount of time you put in, but rather are paid a set salary and expected to get all of your work done in however much time it takes you – with 40hrs/wk being a light suggestion.
Thing is, in many jobs this is simply not possible. So many people I work with will regularly pull 10-12 hour days and receive no additional compensation for it. Honestly, it makes me sad.
Companies will lord “benefits” over your head to convince you it's making up for all the extra time you're giving. But benefits are meant to be part of your wage, not an incentive to devote your life to your company. That's why they're called benefits and not prizes.
(This also relates to tipping absurdly being a part of your wage, and not a reward for exemplary service, but I digress)
More and more companies than ever are also offering these to hourly employees. I currently make around $45k as an hourly worker and get 4+ weeks PTO and decent health insurance, but I also have the opportunity for overtime pay.
I know I'll probably be offered a salaried promotion within a year or two, but I'm going to fight tooth-and-nail to negotiate an hourly wage. There's a lot of unofficially-mandatory overtime in my industry, and I'll be damned if I'm putting in the 60+-hour weeks my coworkers do without being fairly compensated.