I really enjoy playing both Reinhardt and Roadhog, so playing tank is never an issue for me. I can handle healing if need be, but it's a role I avoid unless nobody else is grabbing it; usually go with Lucio as my default there.
But I'm definitely going to adjust whatever I wanna play based on what the team needs. Because that's the game. Not maximizing KDR, not lone wolfing for kills. Teamwork to capture points. If your actions don't contribute to that, you're not helping.