Maining a role VS maining a champ

Ive found that maining a champ is overrated. I used to main Ziggs but even though I do well with him he isnt always the best choice and I sacrifice all the knowledge i have with him to play other roles because I cant always carry with him depending on the game especially if opponent plays really safe and i cant get fed like usual and he isnt that forgiving in a tower dive that really urks me even when I play around it it still can happen and i might rage a bit. So I found Gragas, Malphite , Amumu ,Poppy and Graves. These are burst oriented tanks and they fit my overall playstyle best. I can survive most skirmishes, carry most games, and dont have to get fed to be relevant in most games. I found that by maining this role I can play all roles effectively so if my random teamates want me to switch i have no problem because Ziggs can really only viably go mid. Off meta top, support and ADC.. ive done them all and all so well but teamates get mad cuz its not normal and sometimes fails. So what do you think. Champ or role? by role i mean like AD bruiser, caster ADC, healing supports not a position.