I’m also surprised about there being not a word about smartwatches. I got a cellular apple watch with the idea I could leave my phone at home when doing sportsy stuff like swimming, assuming that a watch with esim support will indeed work with esim. In reality most don’t, Apple is particularly restrictive about it. You’ll probably need some shitty "companion / wearable plan" that most networks don’t even offer. There’s also extra regional compatibility on top of it to deal woth. In the end I never found a deal worth using.

That being said, I settled on esim for my main number and second esim or physical sim as needed when traveling. Having the sim slot free is neat. The biggest downside is "phone gets wrecked and you’re on another continent -> need to authenticate to switch esim to different device -> you need previous number to authenticate -> good luck", but I’m not sure wrecking a phone is more common than having it stolen so it’s probably a wash.

2. trip.com has the lowest prices for esims.