At lower Elo tanks comps are a lot less important since people tend to itemize poorly and play teamfights horrendously. It doesn’t matter how tacky Doom is if he wiffs a backbone yet and your team gets flanked, or your trust rocket jumps in to do more damages. It’s far more important to play characters you are comfortable with and enjoy playing so you get good at them in all their matchups and have a clear understanding of their role at various stages of the game than just running a character because they fit into team comps that aren’t even executed properly at their role. Also if your in lower elo and their executing a tank comp effectively than your probably screwed anyways, since their team play is probably better, and it doesn’t always pay off to hope your team knows how to play around a tank. Sometimes it’s better to play hyper carries, or manipulate waves, so they lose objectives for free or take bad fights when’s 2 people go to clear the same wave. It completely depend on your play style and how well you can execute the champ your on. It’s not just tank up and you win.