Sure, not every moment in life is a teachable or eureka moment. But the more chances people have to interact, the more chances to gain a better understanding of each other.

Without even the opportunity to interact, that divide and chance to learn is zero.

Maybe the 1 out of 100 times, you go to the supermarket, and are feeling good, and feel like just saying hi and do some small talk to the cashier... while it may not change the world instantly, incremental progress is better than lack of it.