Thanos was also a genius, he didn’t run where no one would find him. He knew using the stones would give off the same signal it gave before and that he would be tracked down. He would have easily won, if he wouldn’t have destroyed the stones.
I’d also argue against you can’t kill your way to a better world. When we killed the British in the revolutionary war we created a better world through killing. When we killed the nazis, when we ended slavery through the civil war.