It’s the same as it always was. The issue isn’t Ana, it’s just that Ana is MADE for a game like Overwatch and is actually fun to play. While the other Supports simply are not.
Overwatch is clearly a game like Destiny 2. Where every class is a DPS first and their secondary role is determined by their type of utility. That’s how Tanks are built in Overwatch, which is why they work. DPS get extreme kill power or sides of Support/Tank in their kit. Then Supports get weird restrictions to their DPS (projectiles, weird firing patterns, bad range, mediocre/no damage, etc) and their healing also has strings attached.
Ana and Moira got the memo, so they have some DPS in their kit that’s NOT clunky with healing that’s useful. They can juggle their roles, as they are meant to. They also get Ultimates that are good for any engagement without strict timing required, whereas other Supports don’t. Since Ana and Moira have some DPS or proper self protection, they don’t have to rely on their teammates to save them. Other Supports must flee or kill the threat with their inferior kits. Mercy is the only healer without strings attached to her healing OR inferior mobility, since that’s all she has… But is still at the whim of her teammates so she can never be Ana/Moira.
So again. The problem isn’t Ana (or Moiras), it’s just that Ana and Moira got the memo. They understand what Overwatch 2 is. Mercy sorta got the memo enough to make sure her healing/escapes are good enough to warrant having 0 DPS. The others must’ve been illiterate and couldn’t read the memo, hence their kits’ total power/feel/etc not being on par with everyone else’s power. Healing will always have a use, thankfully. But with characters like Ana, Moira, and somewhat Mercy… Well, why play characters who are handicapped by their very own kits in some way? Just play the Supports who got the memo and understand what Overwatch 2 is.