I am also a DXB resident and with working visa now in my 30th year, however I do project work and this entails living and working in other countries, from Kazakhstan to Morocco and from Pakistan to
Seychelles .................. but I have also lived and worked in Riyadh and Doha
The latter two are extremely safe, but Dubai has problems with cheats and criminals that may use violence/force. It is also prone to all these false calls where people claim to be from a Bank or the Police or ................... - Its easy to check them out - use bad language to them and close the line. Invariouably that will not call back as they know their ruse has been sussed. however, if they do call back upset at your language, then be more serious about the call.
Doha has changed or should I say HAD changed beyond all recognition from a visit I made more than 27 years ago, where alcohol in hotels was just starting in secret bars for westerners and only the Receptionist would inform 'chosen selected' guests. Now it's a hotbed of bars/pubs with unfortunately it has to be said, hoards of drunken QR cabin crew, you know skinny asian types, South Koreans and the like, who just cannot take their alcohol and fall down everywhere rather embarrassingly. There are also better class establishments in the 5* hotels but are very pricy.
So, and contrary to someone here who has compared Doha with Abu Dhabi, as someone who first moved to AD in 1994, it used to be a fun place, but now it's rather staid and boring. Doha on the other hand is pretty wild (Like AD 25 years ago) in some areas, however more costly.
Riyadh unfortunately, whilst being safe and secure (apart from the poorer elements of the Saudi population in the cheaper areas who steal school bus batteries or electric cables etc) however its extremely boring - it's a family, or should I correct that and say a muslim family orientated city and there are zero activities for singletons, unless you might enjoy going for a coffee in Al Tahlia St. The hotels have minimal outlets, as there is just not the same mentality like in Dubai or indeed Abu Dhabi or Doha to go out as couples for nice dinners. During lockdown, I was living in the 5* Hilton Riyadh Resort out on the Northern Road. With over 800 rooms it has just one restaurant and a coffee shop. It is absolutely not a 5* Hotel, but to please the hosts it's given that rating for its grandiose pretentions. Absolutely nothing to do.
Also, it must be said to be honest, the weather conditions are not particularly good in Riyadh, they often give in the daily weather bulletins, the health risk of the air. It's a very dusty, choking particle atmosphere, at times.
So these are my points of view or verdicts on life in Doha and Riyadh. I think everyone knows all about Dubai, as it's all been well commented.
Accomodation, schooling, hospitals etc is more or less the same although the first item had got extremely expensive in Doha in the lead up to FIFA World Cup, but it has cooled down since with the huge exodus of expats, well heeled types as well as the poorer south asians ones.