This has been true even for full-sized consoles until very recently.
Up to the PS3, consoles used to have dedicated hardware which required devs to understand it fully, in order to be able to extract all available performance.
This is one of the reason why late titles were, as a general rule, technically head and shoulders above compared to the launch ones, as the devs acquired experience in that particular hardware.
The Xbox kind of changed that with the "PC-in-a-box" architecture, which made the HW much more predictable but with less margin of improvement over time.
Up to the PS3, consoles used to have dedicated hardware which required devs to understand it fully, in order to be able to extract all available performance.
This is one of the reason why late titles were, as a general rule, technically head and shoulders above compared to the launch ones, as the devs acquired experience in that particular hardware.
The Xbox kind of changed that with the "PC-in-a-box" architecture, which made the HW much more predictable but with less margin of improvement over time.