His reasoning is clear -- it increases surveillance capabilities by the U.S. government. I'd add that it also gives even more centralized authority for the U.S. government to control monetary policy. Even though most banking is digital, USD is still a physical system. The U.S. government still recognizes physical cash as legal tender.
LMFTFY:
"His reasoning is clear -- it increases surveillance capabilities by the U.S. government" - while it is run by democrats and not by republicans.
The moment he will be in power and will need control he will forget everything about how the government must not have any control over this and with whatever pretext, be it money laundering, fighting terrorism or just because somebody has to think of the children he will do the same, but this time it will be good because they are in charge, not the other ones.
Before anyone is giving to much credit to DeSantis remember this:
Should the government classify cryptocurrencies as legal forms of payment?
DESANTIS: No, classify cryptocurrencies as unregulated commodities
He being against CBDC doesn't make him a friend of decentralized crypto.