Nobody really knows and even masked vaccinated people can get the virus. I know of whole families who tested positive and were asymptomatic as well. Also, for whatever unknown reason some people never contract the illness even when exposed.
It's hard to say. We have people good at following mitigation, people who refuse to and people who still get covid when they are careful and following protection recommendations. I would imagine that at some point, herd immunity will be reached and we are all looking forward to that day. I read recently that the virus WILL keep mutating until it runs out of untouched hosts. But I do believe virology generally follows a path of less and less severe infections. But covid 19 is anything but normal so this could break all norms.