tbh the concept of maining a champion is fun for the first 100 or so games and from then on, the returns kind of diminish and it becomes more of a grind as usual.
maining singed for 300 games was fun, don't get me wrong, and I gained a lot of elo from it, but at the end of the day I really don't like how certain champions are completely neglected by riot while others seem to be perpetually in-meta (kench vs thresh) and it isn't entirely due to kits.
I think I learned a lot from maining singed and still keep him as a pocket pick that I can do well with, but the current meta and nerfs to movespeed items are really brutal for him, and riot won't touch him because they remember what a mess league was when singed was strong (druiddroid proxy s3)