Why is there no serious unsharp masking on mobile?

I come from years doing desktop imaging work and recently have started doing some mobile work on Instagram. I've found Adobe's two main mobile products for photos- Photoshop and Lightroom -to be *severely* lacking in sharpening capabilities.

I can't do on Lightroom mobile (seemingly the more professional of the two) nearly what I can do in Photoshop on desktop. The sharpening barely seems to do anything, and when it does, the results are grainy and muddled. What gives? Am I missing something?