For example, Fallout 3 doesn't do a great job of this, as much of the world is baren with no story or gameplay. Half of the world feels like it could be cut out without much loss. The Yakuza games on the other hand, have smaller worlds but they feel massive and fun because there's always something to do moments away.

On the other hand, the world of Fallout 4 feels very cramped; you can't go 5 meters without encouraging something. Bethesda's games are interesting in this aspect – the worlds of different games are built similarly, but they differ in some small parameters (as in the density of Fallout 4), so they're ripe for comparison.

Personally, I feel there were two peaks in Bethesda's worlds – Morrowind and Skyrim. Both for different reasons.