HI! Mercy has in my opinion been a must pick since her Valkyrie rework. Following this rework she has received many nerfs even to this day currently. I want to address 5 primary issues that makes mercy the most well-rounded and viable support.
1.) Mercy has the best mobility in the game.
While I understand mercy has no ability to fend for herself; her ability to fly away on a 2 second cooldown is the strongest get out of jail free card for a support. This ability wastes dive abilities such as winston’s leap, dva’s thrusters, and etc. This is essentially the best way a support can 1v1 somebody, by being able to constantly run away while regening hp and wasting the enemies time.
2.) Mercy has the most consistent healing in the game.
Mercy can essentially heal the most in a game. She has no deterrent when healing due to her healing bypassing shields. She can also heal without making her body visible to the enemy around corners which is unique among healers like ana and moira. Sure u can say ana can throw her nade or moira can toss a ball to heal around corners, but that does not match the consistency mercy has when healing targets.
3.) Mercy empowers dps( Specifically snipers)
Previously people did not have an issue with heroes like widow and hanzo. These heroes lacked the ability to survive. Now that mercy, a pocket healer, is around she keeps them up with ease. This combo is in my opinion stronger than pharah mercy and makes running other comps pointless. Why run dive when u can run a stationary comp that can easily pick off enemies and win fights without having to be careful about positioning(AS MUCH). This comp is picked more CAUSE IT’S EASIER. Imagine the patch notes announced that every dps has a 30% damage increase. Now remember mercy is in ur game.
4.) Rez on a cooldown.
This topic has been covered thousands of times. Rez on a cooldown will never be balanced. People should understand that reversing a pick that took a ton of resources to achieve is almost unbelievable. This is why rez has channeling and makes mercy vulnerable. In this case by rezing she is sacrificing her life to regain a lost teamate. IT SHOULD BE HARD TO REZ SOMEONE. There are all sorts of ideas to fix rez, such as giving it a resource meter like moira or making it an ult again. But we all know that blizzard has no plans to rework mercy again.
5.) Valkyrie
This is by far the second strongest support ult in the game next to trance. It covers the weakness of mercy healing a single target, allowing her to heal everyone, while also providing a strong damage buff to the entire team. This also makes mercy nearly impossible to kill. So difficult that most pros stated they ignored mercy and focused on the enemy team whenever she popped her ult. It is a literal waste of time to try to kill mercy while in Valkyrie unless she found herself in a poor position.
I don’t want mercy nerfed into oblivion, but giving her these minor band-aid fixes is not going to solve anything. Heroes like ana and moira in many games are considered throw picks because mercy is just generally better in every situation. I want mercy to be niche. Just like any other healer in the game, not something used in every situation.