Originally Posted by TravelinSperry

Abroad yes. But domestic, absolutely uncompetitive. I have AT&T Prepaid (for domestic) at $30 per month for 5 GB. That'd be $70 per month for Google Fi (domestic). Absolutely makes no sense to use FI for anything other than a backup phone when traveling abroad. Since they only allow 3 month pauses... you're really paying for them for months you don't use them. And they won't allow you to use them as a backup phone so... as you can see that isn't an option... Google Fi doesn't allow you to stay "consistently abroad". I understand they will terminate you if you aren't consistently using your service in the USA. Users have reported this: "“In 30 days, we’ll need to suspend your international roaming data capabilities unless you start using Fi in the US again. Fi’s terms of service require you to use our service primarily from a US address, but it looks like you’ve been using Fi abroad for over X months.”

So you must use Google Fi as primary at $70 p/mo. That's $840 per year.
AT&T Prepaid for the same 5GB is $360 p year. That means you could travel half the year (6 mos) using AT&Ts 2GB $70 p/mo passport service and still be $50 less than Google Fi. Of course this assumes one uses 5 GB.

I use ~2-2.5 GB monthly. So that'd be ~$45 p/mo with Google Fi ($540 p/yr). That'd only leave 2.5 months of AT&Ts passport for the wash. So Fi could make sense, but really it all depends on how much you travel abroad times the amount of GBs you use monthly.