According to the Zcash chain explorer the number of shielded transactions (private too) are constantly but inexorably shrinking. I am surprised that this is happening also after the release of the migration tool.
Wouldn’t be better to disrupt the market and, temporary, reduce the fees on Z-Z, T-Z and Z-T transactions for at least 1 year?
It might also bring some ‘coins mixing effect’ in the overall picture, that is pretty good for the general ecosystem.