LOL I have a business plan and crappy upload speeds remain. This is a feature of Comcast's shitty outdated dead end RF technology while everyone else has moved on to FTTP.
"Barely adequate" is the enemy of progress.
If you had an area with no service and a sizable customer base then deploying new fibre is viable as you can quickly get a lot of customers.
For an area which is already served by some legacy technology it's much less profitable to deploy something new, depending on just how bad the legacy technology is.
The existing comcast cabling provides barely adequate service for a lot of people, so only a few enthusiasts and heavy users would switch to the new service.
Heavy users cost more to service, if you only have a few heavy users and the majority are light users then the light users subsidise the heavy users.
The existing comcast cabling is a sunk cost, so they have more headroom to reduce prices if a competitor pops up. The competitor has to recover the cost of deploying their new fibre so if a price war breaks out they're going to lose badly.
All of this discourages competitors from entering the market, and with no competitors comcast can keep their prices high. This also gives them vast economies of scale so even if competitors do emerge in some areas and they're forced to reduce prices, they can still keep their prices high in other places to maintain profit levels.