One, companies can’t just pass on taxes like that. If they add a surcharge, that increases the price of the product, which reduces demand. You can’t pull yourself up by your bootstraps: you can’t increase your revenue by having the government add a tax to your product and kick it back to you, maybe unless you sell heroin or something. (But then you could just raise the price without the pretense and people would pay it.)
Two, AT&T is paying the tax, but the government is mostly kicking the subsidies back to small rural telcos and coops. Telcos with more urban footprints, like AT&T, subsidize telcos in high cost rural areas.
So calling CAF a subsidy to AT&T really makes no sense. It’s like saying Apple would love the government to slap a 5% tax on iPhones and kick the money to providers of low cost phones. Even if Apple could increase prices to compensate, and get some of those subsidies for the iPhone SE, it’d still be worse off than without the “subsidy.”
Is this one of the taxes that they just throw straight onto my monthly bill?