You can fry them, they're pretty good.
Weeds are opportunistic. They're outcompeting the grass because that environment is not good for the grass (for whatever reason), but is apparently good for the weeds.
Seed the lawn with native mixes for your region, maybe fertilize, and then maybe the new grass will outcompete the weeds.
Personally, IDC about lawns and let whatever grow. If "weeds" can outcompete the grass, then that's fine by me. Green is better than brown or dirt.
