I wrote the following in another thread that also spoke about Brigitte’s skill. She’s in my heavy rotation, and I’ve adapted to all of her nerfs to come up with good strategies when playing her.
It takes a brave soul to want to play as Brigitte nowadays.
To play an effective Brigitte, you have to prioritize teammates. This can be difficult, but that’s where remembering your team’s survivability comes in. Some characters have their own healing utilities, like Roadhog’s respirator, Tracer’s recall, or soldier’s healing field.
Ideally, tanks should be able to absorb damage, so keep them at arm’s length unless they really need the help. You have to keep a close eye on DPS, or even another Support.
Now, as for playing as her in combat.
Wanna know why she uses no aim?
Because a close ranged character like her deserves respect for bringing a mace to a gunfight. Charging into the enemy is dangerous considering how slow she is, so it makes sense to have a short ranged character get a guaranteed hit if they can survive long enough to reach them. It’s the biggest reward when playing as her, and that’s why everyone hates her. Her rewards are both damaging, effective and fast.
Also, DO NOT UNDERESTIMATE HER ROCKET FLAIL ABILITY.
It has longer range than most people realize, and when you have to take out that Ana who’s standing WAY in the back supporting people with only a quarter of her health left, Brigitte’s flail ability can finish her off.
(True story. I was playing as Brigitte.)
That’s the only thing she does that takes very good aim, and skill is needed to not only pull it off, but also to predict where the enemy is gonna move.
After stunning an enemy, you have the freedom to do 1 out of 4 things:
- Wail on them with your mace. But not just standing in front of them, circle around them while doing so. It works against the ones that like to keep bringing the fight to you, because the overly eager ones are the easiest to outmaneuver.
- Fling them away from you with her flail whip ability. This creates space and allows you a chance to either escape, or force them elsewhere. It also works as a quick finisher in case they may try to make a run for it.
- Run towards your team. This will prioritize team gameplay by making the rest of your team aware of the situation. People think Brigitte is trash right now, so let them think that and underestimate you. They’ll chase you, but will back off if you run back to the Reaper or the Genji on your team. Whoever it may be, running back to the team assures safety if you have second thoughts about the fight.
- Run into an isolated area to recharge the stun. This is the opposite of number 3. Instead of running back to the team, you can dip into a house or run down an alleyway to recharge the shield, and like I said, people underestimate brig, so they’ll follow you unless given a reason not to. Prepare to keep them at Bay with her flail ability also, because this buys you another second to stun them again. After they’re stunned for the second time, they should be dead by now if they’re a low health character, but if not, you can repeat this whole process.
No matter which one of these you choose to do, make sure you have that block button ready.
It’s very important to keep her shield in good condition, but remember, it won’t be long before it’s destroyed, so have another plan ready in case this happens. Like dipping into a house again 
The fundamentals of playing Brigitte is instinct and proper prioritization, which is why skill is necessary in order to know what you’re doing.