I believe Bitcoin will continue to exist and thrive in a world in which there are CBDCs in the most important countries, at least in the civilized countries of the west, it won't get banned from circulation, because there is a lack of legal standing to van a digital asset like Bitcoin.
When those centralized digital currencies start to appear, I would only expect the volume of on chain transactions to go down a little bit, but nothing which could be translated to the end of the Blockchain and the community behind it.
Digital currencies are supposed to be a medium of exchange, Bitcoin at become to be not only a medium of exchange but also some sort of asset for people to speculate with and try to profit out of.

In short, I am very confident Bitcoin will be okey after important countries like the USA and the European Union issue their respective CBDCs.