Cellphone annoyance

My current cellphone is a Moto G8 Power Lite. I have one of the global models because it seemed a reasonable option given that I want it to work in North America, Western Europe, and Southeast Asia. My options are limited partly through wanting a dual-SIM model, for both the UK and US SIMs: I am reachable through either number. My carrier here is AT&T and I am happy enough with them except that next year they are dropping support for everything below 4G and my cellphone's LTE frequencies happen not to intersect with any of AT&T's. Some investigation of band-specific coverage checking suggests that the Japanese model (XT2055-4) of the same cellphone may serve me well enough (LTE band 2 here, 20 in Britain, also 3) but not wonderfully and they are not easily obtained. What do people who travel do, carry multiple cellphones and split their work among them?

It may be that I should consider other cellphone brands and models. For example, I heard that BLU Products offers unlocked dual-SIM Android cellphones cheaply, but something awful seems to have happened to them such that their website is not easily browsed and anything interesting links brokenly out to Amazon who carry very little of their range. It surprises me how difficult it is to find cellphone model selectors that include specific LTE bands as filter criteria.