Due to her distinctive outfit, Overwatch 2‘s Lead Balance Designer Josh Noh acknowledged that Sombra is the most difficult character to balance in the game.
Which character is the most difficult to balance and adjust? was the question posed by a community member at an Overwatch Reddit AMA on May 23, 2024, where players may ask any questions to the Hero design team?

Noh clarified that because Sombra’s invisibility limits her potency, she was one of the more difficult Heroes to balance for the game.
Noh commented, “It’s probably Sombra because her permanent invisibility limits how lethal we can make her.” Sombra was balanced. “But also because she is a hero who possesses excellent teamwork skills.”
Sombra excels in Dive comps because she is very potent if your team is well-coordinated. Sombra is quite limited, though, as it will be much more difficult to dive single targets if you’re wanting to play in a ranked game where nobody is talking to each other.
Noh went on to say that it is challenging to balance several other Heroes since their performance data are so different from how the community views them.
Players in the comments suggested that characters like Reinhardt, Sojourn, Orisa, and Kiriko were the Heroes he might have been alluding to, even though he did not name them.
Each of these Heroes has a controversial role in the meta. Despite their lack of popularity, Sojourn and Orisa have been excellent choices in recent seasons.
While Reinhardt is considered one of the worst tanks to play in the community, Overbuff lists him as one of the most popular tanks among most ranks.
It should be mentioned, though, that Noh stated in the AMA that while Overbuff’s statistics don’t present a “complete picture” statistically, their data on victory rates was generally in line with Blizzard’s own statistics.