You talking about having coding replace outside time.
However, if you look at where most kids spend their time, a lot of it would be in front of the TV or watching online videos or playing games.
I think the people who want kids to code, want coding time as a replacement for watching mindless videos, not as a replacement for outdoor time.
So your kid plays outside and then comes in and instead of watching another toy unboxing video, codes up a simple game they can play by themselves or with their friends.