This makes a lot of sense to me, Phillip. I think I've taken this approach with certain games without consciously thinking about it in these terms.

For example, I'm still playing Death Stranding now well after I actually finished the main story. It's not just that there's "more stuff to do", it's that I'm constantly noticing lots of small details (and entirely new vistas) that I missed during the campaign itself. I want to absorb every drop of creativity from the world as I possibly can. The more I play, the more I recognise the enormous amount of work that went into the project from the development team.

I think the same is true of so many games. I had a similar feeling with Breath of the Wild, as well, which I must have sunk well over 200 hours into by now.