[johnnyanmac]

>you'd expect a company to arrange for this, via just go ahead and .. do it?

Given how the hiring process works (or if I may be frank: has devolved into a soft lottery system), and expectations for most part or full-time employment in terms of scheduling and work terms: yes. Maybe you can get away with finding a seasonal job to do this with, but that only solves half the equation.

many US jobs can barely get medical leave without scrutiny, there's no way this "adult internship" would get approved without some major handshakes. Or as you put it: for people who's so comfortable or confident in life that they can bounce around jobs like this for leisure rather than survival.

>that's probably the result of echo chambers that has stratified the society.

I'd say this is less echo chambers and more how corporate America has evolved. This may have been possible (but still infeasible) in the 60's where you can walk in with a nice suit, give a firm handshake, and be on the holiday shift in a week with relatively minimum contracts or background checks or negotiations (with a single wage that can support a nuclear family to boot!). There's just a lot of bureaucracy even to get entry level stuff these days.