Possible 5G alliance between Amazon and Dish could prove a 'nightmare' for existing US carriers

The (foreign) beginning of a beautiful friendship?
While a brand spanking new 5G network is being built, this is clearly unlikely to cover 70 percent of the country's population within just two and a half years.

The real 2023 number could well end up being much lower than that at the current buildout rate... unless a deep-pocketed partner enters the equation at the right time. Rumored ever since Dish agreed to pay several billions of dollars for Sprint's prepaid businesses, Amazon's name is back in the news today.
Unfortunately, it doesn't sound like the two companies will announce their alliance very soon, as the e-commerce giant is merely planning to launch a "SIM service test" in an unspecified market outside the US at this time. While obviously unconfirmed, the news comes from Peter Adderton (via Seeking Alpha), none other than the founder of Boost Mobile America, who definitely qualifies as a well-connected insider.
Technical resources + money = success
Adderton has no skin in the US wireless game anymore, but his sources are probably as trustworthy as they come, so chances are Amazon will indeed test the mobile network operator waters somewhere outside North America soon. From there, Adderton seems to enter guesswork territory, predicting that an eventual partnership between Dish and Amazon would be a nightmare scenario for Verizon, T-Mobile, and AT&T.
Although Dish already has the (unfinished) infrastructure on which to build its intended "Netflix" of wireless networks to everyone else's Blockbuster, Amazon could provide the essential funding needed to rapidly deploy and expand said blazing fast 5G signal nationwide.

According to the vast majority of pundits, Dish has set a far too modest goal for its 5G network in terms of buildout costs, anticipating a total bill of $10 billion that could easily jump to double that number or even more. Naturally, Amazon has the financial resources to support that difference (and then some), and it may also have the motivation to enter a hugely profitable industry where Dish has a chance to cause "massive destruction of wireless carrier revenue."
While it's not entirely clear where this "destruction" might come from, Charlie Ergen has repeatedly touted a cost-effective network buildout strategy in the past relying exclusively on virtualization. That's not something the other, more traditional carriers can simply switch to without reworking the very foundation of their networks, making it easy (at least in theory) for Dish to beat their service prices... eventually.