There is a wide variety of form factors available in the android ecosystem. Whether or not they fit your definition of "decent" just depends on how much you prioritize size:
Foldables get this job done well. My (OG) Pixel Fold is a great size & aspect ratio while folded, easy to use one-handed, but has a giant screen when you open it up. The newer Pixel Folds and the other foldables on the market have all grown the screen vertically but they're still more compact than most flagships.
There aren't any decent small (less than 6") Android phones either.