Technically the Palantiri were a force for good in the hands of Elves and Men, and could still be used for good, like Aragorn using it to challenge Sauron and forcing Sauron’s hand. So that’s a defense to the self-awareness argument. In fact that ambiguity is likely intentional.
Btw I always wondered why I was seeing droves of Palantir swag on Stanford campus back in early 2010s. I wouldn’t wear something that has a 50%+ chance of being interpreted as evil.