Is it worth of buying it ?

No, whatever you do, don't buy this game. I bought overwatch when it was released and after a few days few of my friends decided to join and they also bought overwatch.
At the begining game was great game had many new mechanics that you haven't seen in other games. It was a good game, but with time Blizzard showed us that they have no idea where they should go with this game. Everything is out of balance. Developers are adding new heroes which makes the game more and more unbalanced. I regret that I bought this game.

If you look for a good FPS game that will push you to your limits, go for Quake Champions. Buy starter pack so you will have all champions and practice or just play with free champions. It is your decision.