There absolutely is. You just think the word immunity means something else.
After vaccination or a passed infection the immune response is there. When a sufficient immune resopnse from a large enough portion if the population is enough to lower the critical cases below some threshold, we call that type of immunity herd immunity.
It's not binary, but a useful concept nonetheless, and one that some people devote their professional lives to. It can be observed every flu season.
what you call "herd immunity" is merely letting people die and then go "we have herd immunity" as part of your survivor bias
only solution that works most of the time, regardless of pathogen (including covid): air filtration (respirators and/or whole room)