I have asked about the bloat on the chain before, and the consensus was that with the visible competition enforcing a 10% tax on mining to afford some privacy, then the storage space used to hold the blockchain would be a much less cost. I would like to know much more about this though, because the blockchain is noticeably larger in this protocol by a lot.
The issue is not only the cost of the storage. There is the download speed also. And other complex factors. A tax is probably also going to have Tragedy of the Commons effects, as I explained in my numerous discussions of why transaction fees will never work for Bitcoin in the long-run. There are other articles out now about these by others. Such discussion will take us off on tangents I don't feel like having right now.
Someone from your group private messaged me and ask I provide references.
I raised similar issues last year as follows.