Here is a summary that lists US Carriers and International data rates. You can see that the old boys Verizon and AT&T have the worst rates.
Verizon is especially naughty throttling your data after .5 GB of usage per day. Both AT&T and Verizon they take data out of your existing bucket of data.
Tmobile has an interesting approach giving your unlimited SLOW 2G/3G data but charging you for calls, texts are free. They do have a nifty 15G of data for $50 add on. Google FI seems to have the best plan with free unlimited data on their unlimited $70/m plan.
Assuming that you don’t want to switch to Google FI and are happy with your current carrier an eSIM seems to be the way to go. ATT and Verizon users may only have a bucked of 2GB of data per month to use when traveling.
Verizon
TravelPassSM
Calls Free
Text Free
Per Week $70
T-Mobile
International Pass
Calls 25c/min or free
Texts Free
Per Week $50
ATT
International Day Pass
Free Calls
Texts Free
Per Week $70
Sprint
International Pass
25c / min
Texts – free
Per Week – included in plan
Google FI
Included in plan
Texts – free
Calls – free
Per Week – Free