Hello !
If you go on this link you can see that optimisation are made almost every update. This game is not perfect, actulaly is not even finish. So please my friend, you paid for a pre-released game. You need to understand that it need time.
When Ark came out, I was not enjoying the game because of the bugs, crash, and lags. So i stop playing it for while and then 6 month after tried again. And I loved it, no more lags, more dino.
Atlas is a bigger project, it will need time. Be patient
Hope to see you on the seas !
Paulo