My DD"s first trip was at 4.5, and at that point we hadn't even owned a stroller in 2 years so it would not have occurred to me at all to use one. It was summer, so we were taking long mid-day breaks from the heat, and never in the park more than 4-5 hours at a time. She never once complained about the walking or tired feet.
When we later had DS, his first trip was at 2.5 and we did bring a stroller, but only used it a couple of times. He was much happier being free to walk and explore, so we mostly just went at his pace, and I carried him briefly when we needed to hurry along. But he did nap in the stroller occasionally. Two years later, on a trip when he was 4.5, we rented a stroller because we were planning some late nights, and I knew he wouldn't last until 1-2am without it. DH thought it was a little ridiculous (again, we had long since gotten rid of ours), but it came in handy in the late hours and allowed us to enjoy some less crowded time in the parks.
In general, I don't think most kids "need" a stroller past about 5, but there are a lot of fluctuating variables that can affect that. (And needing isn't always the same as wanting, and there's nothing wrong with that!) Obviously kids who are used to walking more are less likely to need it, but it also depends a lot on their personality and how independent they like being. I know one time at 3 years old, my DD almost threw a fit because her grandparents suggested that she ride in a stroller (that had been brought for her 4 year old cousin). She was horrified that they thought she was a "baby" for needing a stroller, and was mortified at the thought that someone might see her in it, lol! Whereas, DS at 4.5, was plenty happy to ride once he got tired, and it would not have occurred to him to feel embarrassed about it. To this day, that still very much sums up their personalities!
One thing to keep in mind - you can always try going without and if you end up changing your mind, you can rent one in the park. It's a little pricey, but at least you aren't committed to keeping up with it all day/week, and transporting back and forth.