When Google does it for free, you have to wonder if other carriers charging you $10+ PER DAY just to have data even enabled are charging you because they actually incur heavy costs for it, or if it's just a "Fuck you, you're traveling internationally, so you're probably rich and able to pay it" fee, existing solely to extract more money from a high-value customer.
I'm on a Google Fi Flex plan (I use < 3 GB of data per month), so I pay $10/GB. It's fun landing in France or wherever and getting the text from Google saying "Welcome to France, data is $10/GB". Same price. No extra fees.
Something that I'm pretty sure that has happened, is that I ported a number to Google Fi from Sprint. I am pretty sure sprint somehow blocked something in their system despite reassurances which basically makes Google Fi unusable on their towers now.
Which prepaids? The last time I compared Fi to my prepaid plan they were roughly the same cost.
I understand that "unlimited" plans mean I'll generally eventually hit a limit where my speeds get throttled but $2/GB is not comparable to Google Fi at all.
Obviously, for some people, they won't care about these features/downsides and consider the plan worth it. But comparing it to Google Fi as an equivalent but cheaper option is just misleading.
None of the major carriers can even scratch that price point for a single device. Most are upwards of twice the price per month, plus BS activation fees etc.
I've considered switching to other MVNOs like Mint, but when I take a look at the pricing, it seems like the only way to go lower in price than what I currently pay is promotional rates. And if the price will spike after a year, I'm not interested in going through the process of switching my line over, creating a new account, and all that jazz. Fi works well and costs me a reasonable price per month so I stick with it.
Another benefit: if I ever get a cellular smart watch or a cellular tablet, you can get data-only SIMs on Fi for no monthly cost -- it just shares the same data pool as your phone. That means I could someday run a laptop, hotspot, phone, watch, tablet, etc. all off a "1 person" Fi unlimited plan for $70/mo all-in. Not too shabby.
Most of my time was in South America, I can't speak for overseas if this is the same.
I have never really had complaints about Google-Fi.
I also spend about half every year as a digital nomad.
Doesn't work without a google account. Doesn't work on AOSP (i.e., the carrier switching features are proprietary). Messes up google voice. Massive risk of putting even more eggs in a basket. Also, not sure how long it will be around. It's not price competitive and probably doesn't make Google much money.