Actually, a tablet would be much easier to keep steady than an iPhone as holding your arms close to your sides for stability would be more comfortable with a tablet.If you want to take good quality photos, don't use a huge tablet which is inherently difficult to keep steady. 8MP is plenty for the rare times you will take photos with an iPad Pro.
And if you go to a concert, do not bring your iPad Pro and film the whole thing. Someone behind you is very likely to smash it to pieces.
Why is one relevant to the other? Why do you need more than 8MP? What are you not able to do with 8MP that you could do with more MP? Why are you only concerned about MP and not all the other factors that affect image quality?Why such an expensive high end iPad PRO uses 8MP camera as well?