Here's what I do with an iPhone 13 Pro:
I have primary cell service through T-Mobile (eSIM) . Unlimited plan gives free international roaming, albeit at kneecapped 2G speeds (3G in Canada/Mexico). It's good enough for texts (either SMS/iMessage) and basic Google/Maps searches. You can pay a bit more to add the "double speed" addon which bumps you up to 256kbps (3G or so) if you want to keep things simple.
My phone also has a physical SIM tray that is unoccupied after moving T-Mobile to eSIM. When traveling internationally, you can buy a cheap local SIM (e.g. 10GB LTE), pop that into the physical tray, and use that for much faster data (e.g. Maps, YouTube video, whatever).
Alternately, I've added a Google Fi (physical) SIM into my phone. Google Fi plans have unlimited data with uncapped speeds worldwide (either $70/mo. fixed or $10/GB pay as you go), but you're limited to LTE on iPhones due to lack of 5G support. This is probably not an issue given the current state of 5G deployment worldwide (i.e. nonexistent).
In practice you can mix and match in whatever way best suits you (e.g. personal cell plan on one eSIM, office-paid cell plan on other eSIM or physical SIM, etc.). The critical part here really is that Apple has made it really easy to use two SIMs concurrently, and like with most other things Apple, "it just works"
