https://wccftech.com/galaxy-z-fold-3-apps-use-tablet-versions/

It is not just the physical aspect of the Galaxy Z Fold 3 that has seen a multitude of improvements, but the software area as well. Since the foldable flagship touts a unique form factor and an unusual aspect ratio, there would be a certain amount of tweaking required for the apps to play nicely with the primary 7.6-inch screen. That is exactly what Samsung has done; show the tablet version of more Android apps.

A major issue with the Galaxy Z Fold 2, despite being a terrific foldable flagship, according to reviews, was that the majority of apps would not take advantage of the added screen real estate. According to 9to5Google, Samsung has eliminated this problem to an extent by increasing the DPI count of the Galaxy Z Fold 3 to 673, whereas the DPI count on the previous-generation Galaxy Z Fold 2 was 589.