Looking at the following areas/pain points
1) Proprietary cartridges
2) The experience of the user wishing to print something from a device (connectivity, interface opportunities etc)
1) Epson Tank system did a good job on this.
For the past few years, a lot of people (at least from our side of the planet) convert their printers into continuous ink systems to lessen ink costs. Consumer printers are easily hack with fake cartridges, thus making it easy for individual to use an unofficial ink cartridges.
As mentioned of @cyberdemon, printer companies stay in business because of supplies/ink. Because of the need to save cost on printing, one printing companies (Epson) thought of making a profit on the hardware instead.
Epson is earning through the hardware (not the supplies or ink) with the introduction of the e first ink tank system printer a couple of years ago, it gives a low cost of continuous ink system without the hassle of conversion and voiding warranties.
With this, you have the freedom to refil it with cheaper ink.
2) There are tons of innovation related to this, wherein you can directly print to the device. Airprint is one of the examples.
Again, having a cool- wide- user interface comes with a lot of $$$. You need to consider the memory, touchscreen components etc.
Consumers are accustomed in using iPhone or Andriod devices, they are expecting also to have the same feel in your printer UI.