Why wouldn't a price that's too high to pay prevent a product from selling? If demand of a product goes from 10,000 units to 10 units from the price shift, then it's better to not develop and sell it. The rational move is to focus on the high end or custom-made products where you can have the margins necessary for low-volume to make sense. When it comes to low-end products, volume and throughput is the name of the game.
Want an example? How about this smart move by Framework stopping selling some of its cheapest laptops.
That's a great question. My guess is the bandwidth comes from bonding those extra modes and from the lower signal-noise ratio. That lower SNR means they could modulate with more sensitive but faster modes.