The word “influential” comes to mind, if that’s what you mean. “Powerful” is also good in a metaphorical way. But if you’ve used the non-word “impactful,” you probably haven’t thought through what you really mean to say.
The word “influential” comes to mind, if that’s what you mean. “Powerful” is also good in a metaphorical way. But if you’ve used the non-word “impactful,” you probably haven’t thought through what you really mean to say.