ecos in valorant!

so i'm new to this website and i really enjoy watching valorant/playing not so much.
but how does the eco system work in valorant cuz it seems to me like half/semi buys are just way to good in this game when u combine it with like ultis.

its just too ez when you have scream on your team he just one taps everyone with the sheriff

yeah the half buys are dangerous but honestly full buys would beat them most of the time with a couple of casualties