This is a big assumption. It could also be that it becomes part of the virus background infections we all deal with except that it is high risk if you get it the first time.

When looking that the risk of an non vaccinated individual catching Covid today keep in mind that a lot of people have been vaccinated and the incidence numbers de-facto refer to incidences of the non vaccinated part of the population which would justify a smaller denominator than used (whole population).

That said, there is no guarantee that herd immunity will ever be reached at least in the US. If herd immunity isn't reached then it's basically guaranteed you'll get it eventually as the disease becomes a "background disease".