One Shim Leads to Another Shim
Once you start shimming you will have to do it every time your floor sags down again.
Concrete Blocks can't support a settling Foundation
Concrete blocks only add to the weight on the soil making it more susceptible to settling.
Shimming to the Extreme
Shimming can get extreme after a while. Your more than likely to run out of wood before you fix your settling issue.
Shimming only worsens the issue
When a pier settles the wood around it bends causing the floor to sag. Without a permanent correction the wood will only get weaker after each shim. This causes more damage in the long run.
Woodwork is Vital
If your home's joist are in bad shape due to bad wood work then shimming can even further damage it. Sound support is needed underneath your home.