Your salary isn't determined by impact. It's more related to your market value. Part of your market value is set by yourself, through negotiation. The other

Your salary isn't determined by impact. It's more related to your market value. Part of your market value is set by yourself, through negotiation. The other part is the labor market and what the alternative candidates are asking. Of course impact is related, but only as a qualifier. If your impact doesn't justify the salary then that is a problem. But as long as you do enough to justify your salary than other factors tend to dominate.