It can reduce or minimize the number of cases you spread while infected (i.e. you won't be infected for as long on average), though, and the positive impacts of

It can reduce or minimize the number of cases you spread while infected (i.e. you won't be infected for as long on average), though, and the positive impacts of this at scale are large. (Consider that case numbers grow exponentially, so even preventing e.g. 20% of transmissions in one month will have outsized effects weeks or months later.)