A huge drawback to Google Fi I rarely hear about is that Google is just terrible at customer support. At least with T-Mobile I can call someone, chat with someone, go to a store, get Twitter support, and it's usually pretty quick.
The biggest plus is protection against SIM hijacking, which I agree is a big plus, but no one should be using SMS for 2FA anyway.
I've been using Fi for 3 years. CS has always been hit-or-miss in my experience, but it has gotten worse now that there are a lot more subscribers (thanks to iPhone support and the massive Pixel 3 promo they did last year). They tend to send a lot more generic non-answers, never call back during your call back period (or call at some random hour like 4:30 AM), or just don't even respond at all anymore.
Like many companies, if you keep calling you'll eventually get someone awesome who can pull strings. But it's frustrating.
I've had the experience twice of phones getting lost on the way to me. They would insist on running an "investigation" that could last weeks or never resolve, before they would send a new device. In both cases, I had to be pretty pushy with the agent that the phone either fell off the truck or someone at FedEx stole it. Usually I needed a new phone ASAP due to a failure.
Don't get me wrong, Fi is awesome, especially for international travel. Just show up at the airport and you've got service. The data rate structure is totally fair for how I use it. But there are definitely benefits to having a local Apple Store or Best Buy with a compatible phone in stock.
I've had excellent phone support with Fi in the past, but that was when it was Project Fi.
This outage is a bit worrying though. I'm sitting here waiting for a very important call and now found out, by reading HN, that they may not be able to reach me.
This would be a little bad for Google's free services.
Threads here frequently mention that Google's paid services are decent, but not here. People pay for Google Fi! Not only do they have awful support, but now they have issues like this.
The biggest plus is protection against SIM hijacking, which I agree is a big plus, but no one should be using SMS for 2FA anyway.