OW is basically Team Fortress 3, the only mechanical addition was ultimates with cooldowns. It was an innovation, but saying that TF2 was just CS with abilities is crazy. It was a hero shooter by every metric that makes OW one, unless for some reason you think ultimate abilities are the defining trait. There were 9 characters with very unique toolkits, and most of the OW characters are directly inspired by one of them. The game modes were also lifted directly from TF2.

I liked OW1 quite a bit so I'm not trying to trash it, but it sounds like you never played TF2. If you did it's very obvious how much DNA the two games shared.

From my memory OW was constantly fiddling with the balance from day one -- there were always community complaints about one character or another, and I think the ults being so powerful made it extra hard to balance. Also look at how they had to introduce such hard role caps eventually.

When TF2 launched it was one of the most balanced games you could find with such diversity of gameplay. That got eroded over the years with all of the new weapons which is why the game eventually lost its identity IMO.