I still don't understand why Mercy becomes invincible when using her Ultimate. I can understand the people she's reviving being invincible for a short while, to help them get their bearings. But why should she?
Pharah has to be completely still when using her Ult. Why is she not invincible?
You lose all control of Junkrat for his Ult, why is he not invincible?
It makes no sense that Mercy can just fly into a crowd, pop her Ult, walk around unscathed for a few seconds and then fuck off again.
The change was made because before, when she was basically guaranteed to die when she used her ult, you had to get a really big one for it to be worthwhile at all. I'll give you an example.
Fight starts 6v6.
Enemy Zarya gravs, tracer bombs, three people on your team die (let's say a tank, a healer, and a dps, for the sake of this example, although it doesn't really matter) at the cost of two ults.
You go in and res to bring the fight back to a 6v6. You traded one ult for two, sounds good; but your positioning is problematic.
There's a few things that can happen here depending on what point in the game you're in and how skilled/economical the teams are, but it ultimately boils down to one of three outcomes:
1. Mercy escapes, the enemy team uses no follow-up ults. This is great, but it's unlikely. When the enemy team has killed three and sees that Mercy is not one of them, they'll be gearing up for the inevitable res.
2. Mercy escapes, the enemy team uses follow-up ults. This is by far the most likely outcome in a game with decent players and usually when this happens the outlook isn't so good for the team that just used res unless the recently-ressed players are co-ordinated and preparede. The reason for this is two-fold, but it comes down to the fact that most teams post-res are positioned in a problematic way (such as in the aforementioned example where the three guys you ressed will basically be stacked on top of each other) and, while getting ressed, the other team has initiative. If your team is ahead on ult economy you can often turn these kinds of situations around, but that's far from a guarantee and sometimes there's just plain nothing you can do about it, like if you res into a high noon and your team has no barrier.
3. Mercy dies during the res. Now you've burned an ult but you're dead, so it's 6v5. What's worse is that, as in the previous outcome, your team's positioning is probably pretty bad. Now, sometimes this ends well for the team with Mercy on it, but usually it doesn't. In fact, even though you traded 1 ult for 2, by putting your team in an awkward position you're highly likely to charge enemy ults instead.
I deliberately picked a neutral case. Mercy's ult has always been good when it's, say, 3v4 and you can res two to easily tilt the fight in your favor without excessive ult usage, but because Mercy is such a high priority target res being good largely only in these situations wasn't quite good enough to make her a viable character.
The way it works now is that the third outcome I listed above is no longer possible and in the overwhelmingly likely second case Mercy has the opportunity to position herself somewhere better after ressing, ameliorating the fundamental disadvantage that the revived team will have in that regard. And honestly, while it's made res a lot better, she's still not exactly a powerhouse because it's still often possible for an opposing team to use res against her.
I started seeing dive executed efficiently around ~3800. Nobody even tries it in Diamond.
Can confirm, I had a very similar experience. I'm in the 39xx range these days and dive works here but even in low master people's conceptual understanding of the idea was very week.
My friends are mostly in the 1000-2000 range and they haven't a clue what to do with a dive comp.
