Couldn't agree more.
But as someone who has read Development Psychology extensively for last few years, I have Come to the conclusion that first 2-3 years are most crucial for an infant/toddler.. ( I know you will likely laugh about this.)
Providing Secure-attachment to an infant should be at most priority of a parent. Doing So will take care of the cancer called "Emotional Dysregulation" which underlies majority of mental illness.
Securely attached people are more Independent, Empathic, Honest , More creative, etc.