While their low weight and small size make them ideal for cellphones and laptops, lithium-ion haven't been suited for cordless drills and other things that draw a lot of current. It used to be that li-ion was very delicate, easilyt destroyed by short-circuit or overcharge and hampered by a very high internal resistance. These shortcomings have now been overcome with new robust high drain cells, but only at the price of a much lower energy density. This diminishes the advantage over NiCD or NiMH.
