Most Android devices aren't capable of truly low-latency audio (sub-10ms round-trip). This makes the total addressable market for pro audio apps very small, which means device manufacturers have little incentive to spend the engineering resources to provide low latency, which makes the total addressable market for pro audio apps very small.

Unless Google start setting audio latency requirements, it's a lost cause.

http://superpowered.com/latency

It's a real shame for bedroom producers like me, I've got a disposable income but not a spare grand for an iPad pro (plus I'm an apple anti-fan :-D ).

If Google had sorted out the audio story earlier, you might still have had problems with commodity tablets, but it might have been worth somebody's while to make a tablet specifically for audio and midi. It wouldn't be a million miles away from Maschine or something like that. But I fear the opportunity's gone now, and Android tablets are just a write off.

I still have my Nexus 7 which I basically use as a Kindle.

Those requirements do exist, but only for Android 8 devices, which aren't that many.

Otherwise only Samsung devices are usable, with their own real time audio SDK.