Blockchain will still solve the problem of currency losing value by unlimited printing.
You should be thinking about what problems will retail banking and payment processors be solving. An easy to use CBDC will render many of them unnecessary.
Tangentially, its strange to me that people believe that imaginary money (fiat) should always maintain the same amount of value, when it's an economic tool and not a store of value. The entire point of devaluing a currency is to encourage investment in productive assets while stoking consumption.
Stablecoins aren't an improvement over rows in a database held by a trusted and regulated entity and messages moving between queues for value transfer, but it'll take time for the hype train to run out of steam. I assume boredom will take hold once the ramps are heavily regulated, private wallets are outlawed, there's no more money to be made speculating and pumping/dumping shit coins, etc.
The only way to prevent being diluted is to not hold fiat and end up in a situation where it is held only by government beneficiaries, i.e. that the government is inflating to pay people affected by inflation. Then their ability to inflate is de facto obliterated.