I disagree from my own experience.
I didn't want to do cry it out so we did a 'gentle' method and it took a little over a week.
We established a rigid bedtime routine (and wake up time and daily nap times)
We followed bedtime routine - for us it was bath / book / the same two stories / milk / sleep sack / cuddle / white noise and star light toy. Then baby was placed in cot.
Day 1-2 - lots of cuddles in cot / reassuring words / lay down time to sleep. Until baby laid down and slept with lots of face stroke / hand holds / shushing
Day 3-4 mirror of above but slightly elss interaction with parent sat on floor encouraging baby to lay down at our level for affection
Day 5-8 slowly withdrawing the physical affection so baby would lay down have a small face stroke and repetitive phrase of 'lay down night night'
Then a couple of super easy nights when baby was laid in cot and parent sat near cot 'asleep' and baby fell asleep on their own.
It wasn't without a single tear! But at no point was baby left in their cot crying without a parent right there offering reassurance.
I preferred this method much more than standing outside listening to them screaming until they retched