US Mobile released some updates to their plans yesterday - including updating their "Unlimited Premium" plan to include 10GB of international roaming data in 100 countries (plus 500 minutes/1000 text), per billing cycle. That's in addition to the 100GB of high-speed data (50GB hotspot) that plan offers domestically. This is only on their "GSM 5G" plan, which is T-Mobile based and costs $50/month (their equivalent "Warp 5G" plan which is Verizon includes international data, but it's done using eSIMs that you need to obtain before use so it's as clean).

Likely not the cheapest option, but a fair compromise for unlimited data in the US, and a reasonable amount outside, without having to use eSIMs.

I've been using US Mobile for about 4 months so far, and haven't had any problems with them. Their website/app are good, and service seems fine (although I'm on their Warp/Verizon plan not the T-Mobile one at this stage). They do have a referral program, but as the person being referred doesn't get anything out of it I won't post it here. DM me if you want a link...