This Forum is for feedback and discussion on updates to RS3 that are already on the drawing board, rather than for suggestions.
It is not necessary to make suggestions for things that never left or are already in game. As DrauDaedolon mentioned above, the item lending system is still available in the game, but does not work with many of the newer items that are degradable or not tradable.
If you have suggestions for how to fairly add more items to the current lending system, the
Existing Game Content Forum
would be the place place to post those.