Which is true.
The games are very different. A different control scheme means playing Mercy is even easier than on PC, and aiming and shutting one down is harder on console than on PC. Of course your experience with Mercy is fabulous on console.
Its a different game with different damage values for certain heroes to accomodate the inferior control scheme. Theres a reason the metas are so different and why Mercy will always be much more dominant to the point where I would say she probably should be nerfed on console.
Its a different game, with different playerbase and skill level. Its much easier to perform on a hero like Mercy and harder to do so on aim or mechanically intensive heroes, thus someone like Mercy shines, being able to use Resurrect like its 2017 without being punished as severely as she would be on PC.
Period.