Dynamic shadows on mobiles.

Currently I am working on an arcade game for mobile with voxel art style (made in Magic Voxel). At first I thought, tweaking quality settings and shadow settings would do the trick, i.e. render realt-time shadows on mobile. But this deosn't seems to work. I only have one directional light, minimum shadow distance, no shadow cascades, and only a few objects which are very low in poly count, since they are voxel objects. I am only using Vertex Lit shader for each object, that too from mobile section in shader selection.

While my phone (OnePlus 5) does great (obviously), but many of my friend's phone experience lag.

While those same phones can run Crossy Road just fine, which has way many objects compared to ours. And Crossy Road does feel like they're using realtime shadows, unless someone can enlighten me with the truth.

Is there a way to achieve real-time shadows for mobiles?