Enjoy the title; since that is my buff idea that will be what Ana needs.
Not mobility, not damage; a way to use her kit for the TEAM and SUPPORT them without thinking of Me > The team
Think of Ana’s grenade as a Widowmaker headshot; The most important part of their character where they are rewarded for using it well
The problem with Ana is that she NEEDS to use it on herself to stay alive. So my solution is to give her a weaker self heal (That requires both the spreading of heals, not making her stronger in 1v1s, keep her weak to being jumped on, and rewarding her aim) that allows good Ana’s to be rewarded for the effort they put into the team
Here are some maths; and also 100% perfect situations for each hero involved
Over the course of 10 seconds;
Mercy - After one second, she heals for 20hps; She would self heal for 180 hp
Moira - Is able to live steal for 30hps; She would self heal for 300. With her orb it’s possible to solo self heal yourself for up to 600 hp in that 10 second window
Lucio - While on his healing aura, Lucio self heals for 12.5hps; he would self heal for 125 hp. With the effect of Amp, Lucio would heal himself for 192.8 hp
Zen - After not taking damage for 3 seconds, regenerates 30hps (Shield); Zen would be able to regenerate a maximum of 210 but isn’t fully able to so goes to full health
Brigitte - Inspire heals for 5 seconds, at 16hps for 80 total. It does not increase the more you hit people; 160 maximum self heal over the 10 seconds.
Ana - If Ana has 100% accuracy, and each shot heals for the max of 75, Ana is able to pull of 12 shots in 10 seconds. With the 15% received the normal max is 135hp, if 5 of the shots are boosted the number becomes 163.12hp
So with maths, it proves that even with a buff to self sustain Ana would have one of the lowest if she healed maximum health per shot with 100% accuracy
Still a weakness; but it would be FAR less punishing on Ana and free her up to be more willing to work for the team, rather than the team work for her