If we're lucky the virus mutates into a very transmissible but not very symptomatic or damaging to humans variant. It's speculated that's how the 1918 flu pandemic eventually ended.

That’s true, but before that happened it appears to have mutated into a considerably more virulent and deadly form that dominated in the second wave. COVID probably would eventually burn itself out into a less lethal form, but there’s no telling how long or rocky the road to that could be.