I think the value of digital money is the same as ordinary paper money
It is actually the same value as paper money. The government that has created these CBDC are just trying to say, Here is a digital currency for you to use since you like Cryptocurrency but apart from Cryptocurrencies being Decentralized, can people make profits from any Digital money like you do invest in Cryptocurrencies? of cause not, so another major difference and CBDC can never make Bitcoin worthless.