Dubai is much, much more expensive than people realise. Groceries are insanely expensive and the heat is unrelenting.
My DH worked there for a while and I have a cousin who lives there.
Every single item in your life will cost at least double, so even though people warn good wages, it gets eaten (literally) very quickly.
The US is quite turbulent right now politically.
The UK has its issues, sure. But as someone who has been an expat for the last 10 years, the grass isn't greener.
You can't make up for the security of being in your own country where you can get free healthcare if you need it.
Personally, I would do anything to be back in the UK right now and if I had kids I wouldn't dream of leaving.
The only two places I have lived that have a good quality of life other than the UK are NZ and AUS.
Being an expat used to be more glamorous but the world is a much smaller place now and having things like hired help for your home isn't as cheap as it used to be.
Dubai also has so many ethical issues for both the domestic workers and women.
I wouldn't ever visit there and DH stopped going because the things he saw were vile. Wealthy men with very young Russian girls on drugs, people being put in prison for pissing off the wrong people. Foreigners will never, ever be equal in any way.