re: Avengers Engame - Question (spoilers)

To your point and often overlooked, it took building a special gauntlet, requiring harnessing star power or years of engineering by the smartest people on earth to even hold all five stones before using them. Then even with the special, super rare gauntlet, using the stones once permanently disfigured (I think) Thanos and the Hulk, two of the most powerful beings in the Marvel universe, and killed Tony.

Yes, with that power Thanos couldn't be stopped, but I think he also knew there was no guarantee he would survive using them again if needed. So why not just destroy them and not risk someone else getting ahold of the stones. He just didn't anticipate the Avengers time traveling, but why would he?