Three things:

a.) your German friend would likely have not been in the kafala system since that is for the labour force.

b.) the kafala system has been banned in the UAE since 2005, with a pretty punitive fine regime, although that hasn't done enough to eliminate it (Govt. lenient treatment for its cronies vs independent contractors, both who follow the practice). It's still in force in other countries in the region.

c.) Your friend will likely have been staying at a township for workers, which is often the common pattern for mining towns in most countries in Asia. Conditions usually tend to be luxuriant, and nowhere near the labour camps (which are actual camps).

Oh yes, his position was absolutely privilged. It was the stories of how the local powerful people treated women and the fact that all f them had to turn over their passports. And the curfew covering leave from the compound, that bothered me. Pay was very good so. And yeah, the actual "workforce", e.g. manual labor, construction workers and so on had it way worse.

I had a project in Dubai a couple of years ago, and all the people I was inc contact with were foreigners, on all levels. GM of logistics companies, warehouse workers, manaement, everyone was a foreigner. At the higher levels of management that changes, so.

And don't forget Europeans and Westerners in general have a super privileged position compared to the other workers.