The data for this tracks 2019 - 2022 and so I'd be real curious to know how this would have looked had the pandemic not happened. I think a lot of people's walks often have an objective to them (get coffee, stop at a store, etc) and it just wasn't a great idea there for a while.
I was in Seattle for the pandemic and the number of people outside doing anything at all dropped considerably during that time. I lived by a really popular neighborhood walking greenway thing and it was almost totally dead for a while.