Ana got three buffs specifically cited to help alleviate pressure during RH meta while they worked on ‘fixing RH’ (which apparently meant nerfing him into oblivion with a future ‘rework’ that is in some future, I guess.
Ana had part of just one of those buffs reverted. Ana’s PR/WR was already nearing 100% and >50% before these buffs. The fact that they were not all reverted his hysterical. Even the nerf she just got did absolutely nothing to her PR/WR.
Basically, as long as Ana is as strong as she is, the only reason at all to not pick her is, potentially, she can be fragile. She does an enormous amount of healing, but is possibly divable. This is entirely mitigated, however, by running either one of the other two heavily meta (borderline too strong) supports with her; with a Kiriko who can teleport to her whenever the need calls -and with almost unmissable healing-, Ana (and Kiriko) become very difficult to kill beyond OHKs. So if Kiri is keeping an eye out for Ana, Ana does not even have to pay attention to it and can just keep pumping heals into her tank. If Mercy is on her team, a very similar situation; with Mercy’s buffs she’s gotten so far in OW2, it is very hard to kill whoever Mercy is healing…and she can do it without aim, from range. But Mercy also has the highest movement of nearly any hero, and can get to her Ana very quickly. And if Ana is killed by a OHK, Mercy can just rez it.
Ana/Kiri or Ana/Mercy (or Kiri/Mercy) are just too strong together, frankly. They almost delete the weaknesses of the other by just existing. It sort of goes beyond synergy. On their own, I think Ana is a bit too strong, Mercy is a tiny bit too strong (well, needs reworking in other ways not necessarily related to just buffs/nerfs, anyway) and Kiriko might need adjusting (her WR is not great, but I think she is picked a lot in stall scenarios, which does tank it a bit). These three have been the meta support picks, with little room for any others, for around six months now (since Kiri’s competitive release). We’ve had very minimal attempts (and tepid ones at that) from the dev team to change it. I play support. I’m a GM support player. The role feels as bad as it has ever been.
Because Ana hardly dies (and does great damage on top of her enormous healing), it’s super hard to kill the tank. So fights are just one long drawn out thing. The way around this is OHK heros, and hoping you pick one of those important supports. It feels real trash right now, but it’s been like this for again, nearly six months. We had a brief moment or two in OW2 where you had more freedom. Then back to the same.