I use Google Fi and I've been to the Netherlands, France, Spain, Italy, and Switzerland. When I landed, I'd get a text message saying something like "Welcome to $COUNTRY! Your data is $DATA_RATE per gigabyte and voice calls are $VOICE_RATE per minute. It may take a couple minutes to get connected"
DATA_RATE has always been the standard Google Fi rate of $10/GB (with data free after a certain point, and free but throttled at another threshold), and the voice rate is typically 10 cents/minute.
For people that do a lot of travel and use a lot of data, you can even get an unlimited international data plan.
But yeah, I can go to nearly any first world country, and even some 3rd world countries, and not pay extra for my data. The fact that Verizon/TMobile/Sprint/etc. can't get their shit together and make this happen for their customers feels like a scam.
TMobile provides this same service for free for international travel (I actually wonder if this is where Google Fi gets the service for it from).
Or maybe it is not worth it because the cost of doing so is not worth the possibly small number of people who would use it? A good number of people never even leave the country. I wouldn't be surprised if the vast majority of people in the US leave the country five or fewer times in their lifetime.
But I recently got a taste of that "US based" policy. I am technically based in the US (have a company here) but I have been out of the US since Covid started. Google Fi worked well for about 2.5 years but suddenly when I was in Greece recently, the data stopped working.
When I spoke to customer service, they first told me it's a known issue in the region and I just gotta wait. When I called back 2-3 days later, they informed me that it's my specific account which has been blocked because I've been outside the US for too long.
They billed me for my unlimited international data but essentially blocked me from using ANY data. They said the data will resume as soon as I'm back in the states (which I was in a few weeks anyway). Ridiculous.
This situation really sucks. I'm in the US right now but my Fi data won't work outside the US. Makes it useless pretty much.
There's also an interesting product from https://esim.me/ that emulates the functionality of an esim on a physical sim card, and lets you switch between eSIMS via their app even on older phones like the galaxy S8.
The problem of course is that Fi is U.S. based which brings a few extra headaches with it for people who want the service but are based overseas, or for expats living abroad for a long period of time.
Note: I also have some Voip apps on my phone giving me a few different phone numbers to the same phone without the SIM/eSIM mess. But these days I'm finding I'm more or less just making voice calls over apps anyways meaning I'm using voice service less and less.