It all depends on your device also it changes sizes so they all don't apear the same size. The app is new its takes time for admob to decide whats the best responsive ad's.
One thing people don't realize is 50-70% of what an app earns gets locked up for 13 weeks. So the liquid to pay bills is very small. With out ad's or being popular with the community you can't have a working app.
Esteem survives of earnings and what they make from making post updates which is normally hundreds of dollars each time they make a post on steemit.
Now I didn't question why you had to have them (your paragraphs 2&3). I made a point that they were intrusive and cheap looking. Are you saying that you had no choice over the size?
Perhaps I should demonstrate what I mean. Every other app I have used chooses the small banner at the bottom. It can be a little annoying at times but hey. That's the price you pay... Or don't haha.
Zappl has a banner ad at the bottom which is over twice the height of most others. As you can see in the screen shot it actually obscures some of the post.
So I stand by what I say. Which is not I don't think you should have ads.
But is, it is big and cheap looking and intrusive