AT&T is fundamentally infrastructure, not just service. JetBlue while yes it is service, is also closer to infrastructure than it is concierge.
I distinguish services vs infrastructure based on if they are fundamental needs, not how they are provided. So water treatment is technically a service, but it's a fundamental piece of life so it's infrastructure.
Are telecommunications and flight fundamental needs? Humans lived for hundreds of thousands of years without them. Yet I agree that they are infrastructure. On the other hand, humans have not lived for hundreds of thousands of years without food, yet I would consider McDonalds a service.
Personally, I think the distinction is in how it is provided. The copper/fibre line to your home is what AT&T has to bring to the table. JetBlue brings their fancy flying machine. The water treatment plant has their water treatment system. While people are certainly involved in the process, the defining feature of these businesses are related to the machines/technology that they possess.
On the other hand, McDonalds certainly has a kitchen, but so does everyone else. They are literally found in almost every home. What McDonalds, and restaurants in general, bring to the table is a person willing to do the cooking and other related activities for you. Because the defining feature is related to human labour (for now, at least), these are services.
I distinguish services vs infrastructure based on if they are fundamental needs, not how they are provided. So water treatment is technically a service, but it's a fundamental piece of life so it's infrastructure.