it seems logical that earnings should improve.
I don't really follow your logic.
Ad impressions are awarded based on the highest paying ads. If a network that is paying 0.80 Euro and it is not filling all the impressions, that is not because there are 0.30 Euro ads preventing more impressions. Its is because there is not sufficient demand for more impressions at that price point. If you want to show more ads, you drop the price.
For example you have a supply of 100 impressions:
Revenue to impressions will likely be distributed as follows:
100th = 5$
95th to 99th = 3$
85th to 94th = 1.50$
70th to 84th = 0.75$
50th to 69th = 0.50$
30th to 49th = 0.25$
1st to 29th = 0.03$
Blocking the networks that fill the impressions in the bottom of the distribution will not suddenly cause those impressions to be sold at higher prices. To the contrary, it will allow buyers bidding lower to win impressions that would have gone to higher bidders so the 0.03$ impression will now be sold for 0.02$. It is also very probable that all the other prices above will drop too, due to less competition. This is basic supply and demand economics.
If you want to see the distribution of prices in your account go to the "Reports" tab all the way to the bottom, the before last element is "Revenue Profile". This report shows the distribution of impressions by price point.
If you want to increase prices, there is only one way and that is to increase demand. Which is much easier said than done.