Google Fi, as a Google product, has effectively zero customer support, so I don't think an attacker could social engineer their way to a sim swap. /s, only a little.
Actually, their customer service support is very good. Source: I've had to call their customer support. I had an issue with my VOIP number I ported over not working properly, they fixed it.
They'll probably prevent a sim swap, but I don't know about not using my personal data.
