It wasn't long ago that Google directly employed most of their datacenter techs. I know a couple guys who worked their way up from server monkey to SRE. It's sad to hear that that pathway seems closed off.

If you get a guy to come replace your roof, it's not really your problem that his employer didn't give him a water bottle, now is it?

Sure, but if I own a house construction company and hire a contractor to do the roofs because I want to keep roof costs down at all costs I am responsible for the low salaries and poor conditions of my roof contractors.

being a good client I would still offer them water/soft drink regardless.

Yeah, it kinda is, unless you're a total shitbag with no empathy.

If the contractor doesn't pay the subcontractor, you as the homeowner are liable.