Question

Why do you think rulers in ancient times recorded their victories on hard surfaces like rocks and pillars

Answer 1

so that future generations remind this and thought about victory of their ancestors

Answer 2

the rulers in ancient times recorded their victories on hard surfaces like rocks and pillars as wanted to spread their game throughout their empire. when words are scratched on hard surfaces the cannot be erased out and thus stay in the same state for a very long time.

hope that helps