it's harmful because it when it is wrong, then it can cause a lot of damage to the relationship. what we think others are feeling is always based on our own feelings. the reason it works, because most of the time, their feelings don't actually matter.

when bumping into a stranger, assume best intentions, apologize or say something else appropriate and move on. who cares what they actually think or feel.

the closer the person is, the more communication is warranted.

There are plenty of things we evolved to do/believe/think/perceive that are now harmful, because the world has changed and we haven't yet genetically evolved to fully adapt to it yet (and, because of medical technology, we may never do so). There are hundreds of cognitive biases that exist because they were an evolutionary benefit, but no longer are, or are no longer enough.

Predicting how people feel is empathy, and that's great! But stopping there and assuming your predictions are correct without actually verifying them with the person first? That's harmful. You're not too busy anymore running from lions and hunting deer to stop and talk to a person before forming your ideas about them.

We're not on the savanna hunting antelope anymore, so knowing that you're feeling, "scared of being eaten by the lion behind me" is no longer granular enough to be useful.

Human ancestors evolved social skills way before they descended to the savanna. Chimps kill each other all the time, maybe evolving a way to predict feelings would be useful there?