Comment by reustle

Yes, but the whole reason for using Twilio is so you can hack your telephony just the way you like it. Google Fi does not also have a ton of cool services you can take advantage of. You get a phone number and that's that, you're subject to the same old POTS-like restrictions. I don't suggest people use their Twilio SIM card for data like you would on your regular phone, even though when you look at IoT data services offered by companies that aren't also enormous wireless providers, Twilio's prices are relatively pretty good. And also calling and texting is dirt cheap but again, not like with your regular phone. I have a phone with two SIM card slots, and so I've got my regular stupid phone provider's SIM card in one slot and the Twilio SIM in the other. New versions of Android give you tremendous granularity of control with multiple SIM cards, so I can be hyper-specific about which activities should be using which SIM cards. And this granularity is very well-designed from a UX perspective, making it almost effortless to override my preferences e.g. for making a single phone call or using one specific app for a short time.