I think its worth talking a little about our balance philosophy here. People often will post things such as “why doesn’t Blizzard see that this hero has X as a weakness and that is what should be fixed.”
One aspect of our heroes that is very important is that they all have various strengths and weaknesses. This is a core aspect of what makes teamplay so important in Overwatch. If you have an Ana on your team, this gives you certain advantages such as being able to be healed from very long range, having a more offensive-favored ultimate, and having the ability to disable healing on enemies (which can be especially vital against heroes that really rely on healing such as Roadhog). That said, she also brings her own weaknesses that must be managed, such as low mobility and lower self-healing. A team may opt to run Brigitte or Lucio with Ana to help peel attackers off of her, for example.
When we want to buff a hero, sometimes it can be the right call reduce these weaknesses. For example, if a weakness is just too overbearing or a hero just has too many weaknesses compared to their strengths. But more often we would rather amplify a heroes strengths and make the hero just better at what they do, which leaves their weaknesses still around for enemies to exploit and for allies to try to manage.
I hope this helps explain how we look at balance issues and heroes in Overwatch in general.