Sit and stand stroller or not to bother?

Ally • Expecting a baby girl in December!!! 🎀
I have a 4 year old and im due in December. I was curious if other moms have purchased sit and stand strollers for their children or if 4 years old is too old for a stroller in general. We use the wagon for zoo trips now. And if you suggest to get a sit and stand stroller what brand do you recommend?