Well, here’s how I’d do that.
Give Tanks more headshot damage, but also give Tanks headshot resistance, then maybe lower their HP.
Scribble notes, Tank fix
And otherwise nerf Tank hardcounters like AntiNade, StormArrow and Bastion Sentry
And beyond that, make Orisa and Mauga more AntiSquishy and less AntiBarrier (I.e. More headshot and burns, less base damage, more spread)
But ultimately the bottom line is that Tanks becoming more Fun, will make some DPS/Support players have less fun. But that’s fine. As long as it grows the overall playerbase size.