Hmmm, I don't know. There are so many factors. My sister's kids used stollers way too much, imo. They are both skinny minny teens now though, however they are both rather sedentary and will likely become fat adults someday.
I only used the stroller, after my kids were good walkers, for outings where I needed them under control and my attention couldn't be on them. Things like doctor's appointments or when I had to take them shopping when I had to get stuff. I try not to take the kiddos when I have stuff to get done.
If I'm taking them for their benefit, just to have fun, I do not use a stroller. I quit taking the stroller to the zoo by age 2. We have a zoo pass however and don't spend more than 3 hours there at a time. My kids don't wear down that fast, they prefer to walk/run through the zoo.
Most of the time, I do not use the stroller, but it is nice to have on hand in some cases. I don't have family in the area, who can watch my kids, so it was nice to put the youngest in the stroller with a few toys while I got my teeth cleaned, that sort of thing. Now, my oldest can watch the others for brief periods so that is very helpful!
The other day, I saw a very heavy woman chasing an active toddler around the play ground. After a few minutes, she strapped him into a stroller!
Why take a kid to the playground if you won't let them play? She was clearly a bad parent anyway as we left quickly due to her older children's use of swear words. It was clear that that kind of talk was used regularly and acceptable in their home. Things like calling one another "a-hole" and causally using the word "f-ing".
ETA: If my kids were closer together in age, I suspect I would have used strollers more and for longer. It is much harder to take s two or three very young ones anywhere and safely keep track of them. As long as kids are getting exercise every day, stroller use shouldn't be a factor.
