If they recreated it from scratch though, I don’t see what was stolen. Unless they incorporated your implementation somehow, I can’t see how this rises to stealing. There can be many competing implementations towards the same spec, and using one over the other is not necessarily theft.
Covid is now endemic and no longer an epidemic/pandemic, so the need to contain cases is less immediately important. I, too, still like to wear masks in super crowded places or if I’m not feeling well but it is rare.