I have them in the lawn.....they must turn into something, don't they? Sure, they eat the roots of the grass, but I can live with a few brown patches if they are something interesting eventually besides just a grub.
CLOSED: What do lawn grubs turn into?
Beetles. Around here, it's various June 'bugs' (really beetles, not true bugs) and Japanese Beetles.
Around here they are mostly Japanese Beetles. When I was doing maintenance at a golf course nearby, we used to have contests to see how many grubs we could gather in a day. You don't want to know what we did to them. Our Super had a motto that one grub was one too many. :0)