I have a couple of hundreds (600?) hours in Overwatch and 18 hours in Paladins and played Team Fortress 2 for 500 hours. To me, they share the same game genre, but are different. Overwatch feels much better balanced and mature. To me, Paladins feels a bit sheep and I am not a friend of the power up mechanics. I wouldn't it call a copy of Overwatch, just because they are same genre. There is a chinese game, which is really a copy of Overwatch.
> https://www.vg247.com/2016/06/16/theres-a-chinese-overwatch-rip-off-and-it-looks-terrible/
Look at the video.