Why would the government want to take our guns unless they will be doing things that warrant us shooting at them?
What, like Trump declaring himself president for life?
But here's more normal answers:
Dead people can't pay taxes. Less guns, less people being shot.
Lower cost of police. Less guns, less need for hyper-awareness, less need for special equipment like bullet proof vests. And lower health care costs for them. Also, it becomes safer so you have a better chance of hiring people.