Your oldest was probably an outlier. It sounds like you did the opposite of what he needed and I doubt he appreciates it and his discontent will only grow around this as he ages.

I am the oldest. My younger siblings are like your young children. My parents would say the same thing you did. Because I turned out the most competent. I was their "problem child".

I don't credit them with my success. They were idiots. They made it all so much harder.

They were too stupid to see how exploitative the system is and help me adjust for that. Instead they laid it on me to figure it out and raise myself.

Good Luck, you are in for a wake up call.