both Xamarin listview and Telerik's Radlistview, for some reason, has expensive binding and initialization. this cause to performance penalty.
luckily, there is a solution for that, called fastcell.
I have tested the library, and indeed performance are much better, especially on old devices.
however, I couldn't find a way to integrate the fastcell with the telerik's listview.
also there isn't a custom renderer for cell, so its not possible to override it.