It's too big of a topic for a HN comment but do a google or LLM search and see. One widely-accepted aspect is that a child can not "self soothe" until 5-7 years. It's not developmentally possible, and using that language is a bit of a PR move to gloss over what is actually happening.
https://www.google.com/search?q=infant+co-regulation+vs+self...
https://en.wikipedia.org/wiki/Emotional_self-regulation