WiFi for data, and you can still receive calls but they are pricier. I’ve got 2 contracts in different countries, I tend to switch my Sims across as I also have 2 WhatsApp accounts but they won’t let you register more than one device to each, unlike telegram or signal.
The UK may have some options, it’s a fairly diverse country. Crime can be an issue, but probably not so much in areas where the work would be available.
I would avoid the middle east, even though it’s safe and super diverse. The quality of work would be at your detriment, getting a job outside that region would be difficult after some time.