This is actually true. Healing/supports are those who make the balance insanely difficult in this game. Healing in OW is esp. cheap and strong compared to other PvP games which have healing too.
I remember my team and the enemies play without supports long ago before RQ. Everyone was either tank or dps. Widowmaker was nothing. Tank stacking was also nothing. Niche characters felt also much better(or too good sometimes).
I wouldn’t say remove healing because then it is not OW anymore. But I’m pretty sure behind most of the problematic meta, a BIG amount of healing supporting them is hidden.