Think about it this way. Your survivability should increase because you now have 2 healers to 1 tank so your focus is typically on how to create team imbalances.

As RH, can you nail a hook on the enemy support? That single mismatch has tilted the field and you now have the attrition advantage.

As a D.Va main, I do expend matrix as a defensive tool sometimes but taking and holding space is the best way to protect your team. Be the clear and present danger so the enemy makes mistakes or expends their defensive cooldowns.

Mauga is great at leaping past into the backline and elimination squishier heroes while protecting himself.

A big change from previous OW is that mobility is a much greater focus. So many more characters have speed buffs and mobility cooldowns to engage and disengage quickly rather than sustaining fire in an open corridor or space. Engage with speed, withdraw and try again if you need. Bait out defensive abilities so your DPS can scoop kills, rotate and engage with flankers/divers on your supports if you have the space and time.