This is why I don't bother with estimates any more - not because I think it's impossible, or even necessarily too hard, but because I've observed (consistently over a 30 year career) that it's pointless. Even if you could estimate with perfect precision exactly how long a software task was going to take, they would just push back, say, "that's too long" and argue with you until you told them what they wanted to hear.
This is why I don't bother with estimates any more - not because I think it's impossible, or even necessarily too hard, but because I've observed (consistently over a 30 year career) that it's pointless. Even if you could estimate with perfect precision exactly how long a software task was going to take, they would just push back, say, "that's too long" and argue with you until you told them what they wanted to hear.