I also do this. Xfinity went out for a few hours earlier this month and Unifi failed over almost instantly, and within minutes we had high speed internet once I upgraded us. The standby mode would have been plenty for basic web browsing, too.
$5/mo for pretty guaranteed connectivity, plus being able to take it around with me on travels is pretty awesome.
What is the role of Unifi here? I read the article and went to their site but I still have no clue.
I was paying for gigabit with the local ISP and it slowed down and lost connection so frequently I bought a Starlink (the regular one, not the mini) as a "backup."
As per the usual, my internet went down and I switched to the backup Starlink. After working with it for about a week I cancelled my ISP.
Turned out around 350MBPS down was fine for everything I was doing (and it's way more reliable).