To be fair, nobody outside the company knows if Fi/Fiber/Pay are viable businesses, or they are on life support but still around because of the unlimited cash Google has. One can guess they are profitable because they have been around for quite a while and still kicking. But nothing says they won't be the next thing in Google graveyard -- plenty of services seemed to be doing ok before a major reorg sent them to death.
Google Fi is just an MVNO, and there are quite a few competitors in this area (e.g. I'm using US-Mobile). They have comparable prices, so I'd guess that Fi is at least not operating at a loss.
Existing Fiber customers are basically a free money printing press. That's not going to change. But the new area buildouts can slow down.
Honestly, Google has been so un-innovative for so long, that it's hard to make a case for them. They just don't have a lot of products that are really benefiting from being under the umbrella of a large company.
I can definitely see an argument that back in 2006, Google Docs would have been impossible without access to the internal Google infrastructure and the unique expertise of Google engineers. These days? It's just a run-of-the-mill cloud application that can be trivially hosted on commercially available AWS or Google Compute.
Perhaps treating Google as a huge VC company would be more fair.
