I've been exploring the US Mobile plans since enrolling in the "Warp 5G" service a few days ago.

They have a nearly perfect travel plan based on T-Mobile domestic service for $50 a month (Plan is GSM 5G, Single Line=$50, 2=$90, 3=$120) inc. taxes & fees. It includes 100Gb of 5G high speed data & 50Gb of hot spot in the US. The place it really shines is in the included international features. You get 10Gb of high speed data, 1000 texts, and 500 minutes of calls in 102 countries around the world per billing period. Oddly, the 500 minutes of calling does not include calls to the US, but I think WiFi and IMS functions are easy and practical for those calls.

They have sim cards and esims, and a decent phone app. The web site is easy to navigate and use for info and account details. I must say, if I didn't already have T-Mobile with grandfathered roaming service, this would be a serious contender for domestic and travel cell service. I have only contacted customer service once, but comments are generally quite favorable on Reddit from current users.

These features were introduced around 9-20-23, so take a look if you haven't been there lately.
https://www.usmobile.com/

Edited to add: In backtracking this thread I discovered I had duplicated docbert advice with my posting about the recent version of US Mobile's plan for travel. I apologize to the community and especially docbert for this faux pas on my part. They say never ruin an apology with an explanation, so I'm sorry for this apparent plagiarism.