But giving feedback is a lot more helpful in so many contexts and in important skill to learn and grow from. It’s not the same (or shouldn’t be the same) as a white lie

You're coming at it from an, "I want to grow and learn as much as possible" mindset. That's not the mindset of most people in general. Most people just want to get through the day with the least amount of hassle and upset as possible so they can go home.

You're looking at it from an almost clinical or Vulcan-level logical point of view. Neurotypical people don't typically exist that way, at least the majority of the nice ones don't. For neurotypical people to take feedback that way, they almost have to be on a different level of consciousness.