If data caps were lifted then mobile Internet could be a viable alternative for a landline connection.
Why does mobile broadband still have data caps? Why haven't then progressed along like landline data / limits did and eventually were removed? Or is it just an evolution thing and eventually they will be removed too?
If they lifted the data caps the service would quickly be over saturated and crippled.
Unlike with traditional broadband where you can just add another backhaul pipe when demand/usage increases, 4G has limited spectrum.
They would need to reduce power/reach of masts, and build many more masts, to be able to offer unlimited data the way you want.
All that extra equipment needs paying for and that may significantly increase your mobile bill.
They don't have the caps on data just to screw the customer. It's a necessity to keep usage at a level where the equipment can keep up.
4G as it is deployed by mobile operators in the UK isn't suitable as a permanent replacement for everyone's broadband. It never will be.