Cellular data unusable during Xfinity cable Internet outage

A couple weeks ago we had an Xfinity cable internet outage in our neighborhood that lasted about 12 hours. During the outage Xfinity cellular data was virtually unusable--couldn't send iMessages (did not test strictly SMS messages--will have to try during the  next outage, which happen 2-3 times a year), email, couldn't browse websites (browser tried but eventually gave error that it couldn't reach the server), or use other apps. So basically without any internet because I'm "all in" with Xfinity--mobile and cable. Thankfully, I didn't have any extremely urgent work or life matters that required Internet.

During the outage, I contacted Xfinity mobile support and eventually my voice call got elevated to the next level and the rep began a chat session and opened a ticket with the cellular tower provider in our neighborhood (Verizon--chat is the only way they can communicate with the tech support of the provider so it's a slow process). The rep asked for my email address and said the ticket could take up to 72 hours so Xfinity mobile support would contact me with the resolution (stupidly I didn't get the ticket number).

Cellular data came back fine when the Xfinity cable Internet outage ended.

Several days late (more than 72 hours) I hadn't heard from support so I initiated a Xfinity mobile support chat. Chat didn't know anything about the ticket so I had to start from scratch and eventually ended that in frustration (even after communicating with an unhelpful supervisor for a while) and called voice. They also didn't know anything about the ticket, but to their credit tried very hard to get info and eventually said they found that the ticket had been resolved by the tech support of the tower provider (I assume it was "resolved" because the Xfinity cable internet outage ended). Why doesn't Xfinity mobile support chat have visibility to notes and logs from Xfinity mobile voice support?

To make a long story short, I assume the Xfinity mobile cellular data unusability was a result of other Xfinity cable Internet customers, who are not Xfinity mobile customers, taking all the bandwidth by using their unlimited LTE and 5G cellular data with their providers (like Verizon) for all their Internet tasks, including I assume streaming, and being prioritized over the Xfinity mobile users (because of the contract between Xfinity and the tower owner, I assume Verizon, that prioritizes Verizon customers' cellular data).

This issue is exacerbated because I assume there is only one tower usable from my house in our neighborhood. 

It is an issue because it's pretty important to be able to use cellular data at your home in a wifi/internet outage situation. Xfinity mobile certainly doesn't disclose to or warn potential customers or switchers that this may be the case in a situation like I've described above. Of course, during the outage we left our neighborhood to do some shopping and cellular data was fine when we were outside the Xfinity cable internet outage area.

Would appreciate some higher levels of Xfinity mobile support weighing in on this very important issue affecting whether customers should switch to Xfinity mobile.