Would you prefer society just ignores this inconvenient fact?
The risk of developmental issues was obvious to many people at the beginning of the lockdowns. Now we have some data. It will help us make better decisions in the future.
Anecdotal, but I have a 5 and a 3 years old and missed nursery has been terrible for their development.
You don't even need a study for this, it's just common sense for people who have interacted with a toddler in their life before and after nursery (after 2-3 years old, I wouldn't recommend sending them before - they tend to not be ready for social life and not having one dedicated adult to them)
The risk of developmental issues was obvious to many people at the beginning of the lockdowns. Now we have some data. It will help us make better decisions in the future.
Every choice has consequences.