I’ve visited Dubai several times...the most recent visit having been last month.I don’t know about “slavery†but several things are easy to see.1) There’s construction *everywhere*.2) Those construction sites are manned almost entirely by small,very dark skinned men.If you look closely you understand that they’re from India,Pakistan and Bangladesh.3)These men work in the most appalling heat. 4) Early in the morning and later in the day you see these dark skinned men being transported to/from construction sites in the most God-awfully maintained buses you can imagine,...death traps on wheels.That may,or may not,be slavery but it sure doesn’t look like fun.
I've been to Dubai many times and know exactly what you are talking about.
These workers are indentured servants. They sign contracts to come and work but before they earn a dime, they have to pay for their passage. And then they have to pay for their room and board. If they get injured or sick, they are sent back with nothing. At the end of the day they are practically slaves in all but the most literal definition.
And their lives are cheap. You probably noticed an absence of safety equipment being utilized by the Pakistanis working atop skyscrapers. This is because safety equipment is expensive whereas Pakistani laborers are not.
Very few of them ever earn enough money to have made their trips and their labor worthwhile but there are so many of them, they keep coming.