Why only the IP series is functionally reduced?

For years I printed with iP4500 is fast and economical (because with substitute ink cartridges). The paper just ran from top to bottom through the printer, this could easily also photopapers find 240gr / m² use. A lower tray could also accommodate DIN A5 formats. Unfortunately, the printhead was after 5 years at the end, the whole to be found on the net cleaning tips and YouTube instructions not helped ....
The iP7250 has 2 lower paper trays, one for formats and A4, the other for photo paper smaller A5 (!), A4, must be turned as in prehistoric printers in the printer (major problems in strong paper), the printer will be slower, the capacity of the cartridge is less, the cartridges are more expensive. OK, it has Wi-Fi and is lower.