You can normally get "studies" to support both sides of most debates. So it boils down to choice. (If you are lucky enough to be in a position of choice)
OP, you need to just do what's best for you and your child.
But it does largely depend on the care and input they would receive at home with their parent. Also the financial implications of one person being at home for 3 years or 2 people splitting that time off, it's no good having a parent at home, if the family then can't afford to feed themselves, it no good having a parent at home if said parent is going to be unhappy there, as they will resent being there and want to get back to work.
Same goes the other way around, there is no point sending a parent back to work, who doesn't want to be there, if they can afford not to and don't want to pay someone else to be with their child most of the day. Our DS was so full on, he was 100 miles an hour each day, every day, I loved that, i know some parents can't keep up with their kids like that or dont want to, it can be exhausting. He was so inquisitive, but I loved being there to teach him and nurture him, I know for our family it was the right choice for me to be at home with him. It would have broke my heart having to send him to nursery, but again that's a personal thing, I did ensure i kept my social life as well and my interests going, but it really depends on the home situation on where makes a child thrive most, so always just do you.