What if we add a new role to the game, something akin to what Brig was supposed to be (I know, Brig killed the game blah blah, stick with me here). Offtank/off healer hybrid. Then you get 3 dps in each game, main tanks and healers both have backup, and you get a new flexible and engaging role.
Comps become
Tank -Rein, Orisa, Winston, Sigma, Ball (wtb new Rein style tank with different abilities)
Healer - Bap, Mercy, Moira, Ana, Zen (2 orbs of Harmony that do 20hps, slightly nerf damage)
3 dps
Hybrid:
Zarya - can use her weapon charge to heal allies, or give them shield health. Depletes weapon charge.
Brig - 400 health shield, twice as big, regens fast. No passive healing.
Hog - vape cloud like experiment
Mei - ice blocks allies within 5m of her when she blocks. Unnerfed wall
Sombra - can move hacked health packs (1 at a time)
Sym - Traveling shield instead of tele, turrets heal instead of damage. 10 hps each.
Lucio - additional aura type, distortion. Causes his skate trail to leave a 1m wide distortion field that reduces damage of passing projectiles by 30% (so he’d have to wall jump passed allies to actually protect their torso/head), lasts 1s
Ideas are obviously rough, but you get the concept.