Getting better

So I main gangplank but I play every champ I own which is around 90 or so I play why do I play so many because I get bored if i play only a few champs really quickly, for example mechanical wise im great with GP and udyr and lackluster with many others but if I play either of the characters im really good with too much I don't want to play them anymore but I realize playing too many champs you won't get better but that leaves me in an odd position