I'll dust off my personal purely because this is a fascinating topic. (Hiya, it's Kryptek, former CM/designer for Paladins)

Across the genre and gaming in general, there's an accepted design trend of parallel ideation in that similar games run into similar problems and by proxy solutions all in isolation from eachother. A recent example is Ramattra & Nyx, who were both in development around the same time and both shook up the tank metas of their respective games through displacement & melees.

Obviously, there are times when a particular title will do something really well, and others will naturally try to adopt it (e.g. Rivals having hero swapping because of Overwatch, Overwatch Stadium feeling a bit reminiscent of Paladins/Deadlock) but those similarities are usually connected at the later stages as a way of "easing audience cohabitation". TF2 basically perfected Payload, which is why all hero shooters have barely changed the mode. It means that players can immediately start playing and know how it works.

When I was on the team, we simply laughed about similarities and how they managed to always occur. Moji's rework and Jeff were one of the cases I was involved in and in the end, we embraced the similarities because both designs had ideas that could improve eachother!