First of all, it's great to see you more active on the forum 
Second of all, I really appreciate the thoughtful post!
Third of all, I don't really agree
For me, Breath of the Wild is the best open-world game ever made, yet it has a very uneven balance between "overworld" and "underworld". The overworld is phenomenal and the underworld is relatively underdeveloped. But I think that barely makes a dent on the overall excellence of the game, because it excels in so many other ways: tactical, improvisational combat; a wistful, poignant story; quirky, lovable characters; expressive art direction; immersive sound design; realistic and predictable chemical, physical, and mechanical systems that encourage and reward creative problem-solving and outside-the-box thinking; the feeling of joy and accomplishment when discovering something new; the sense of solitude and wildness; and a deep commitment to player agency and emergent gameplay.
In other words, I don't think the recipe for success is as simple as good overworld + good underworld. Other things make a major impact: moment-to-moment gameplay; controls; art direction; narrative; puzzle design; atmosphere; interactivity; etc.










