Scam has been existing before cryptocurrencies were created, in this modern time, people still mostly use fiats to scam, even if bitcoin and all other cryptocurrencies are banned, scammerw will still always make use of fiats to scam. There are many ways scammers o this successfully in a way they can even not be traceable. In some instances, bitcoin and other cryptocurrencies are traceable than fiats.
Fiat currencies are used for everything way more than Bitcoin, so it's really a non-statement to say that fiat is used more for scams, money laundering, etc. Just because this problem exists with fiat, doesn't mean that we should ignore it in Bitcoin. After all, we all dream about a world where Bitcoin is used for everything, so we need to be ready to solve those problems.
Traceability is only one part of it though, immutability is also playing the role here. I believe Bitcoin really did contribute to the growth of ransomware, because most ransoms require Bitcoin or other crypto, and this scheme wouldn't work well with any centralized payment system, as accounts would be very quickly shut down, and large sums of money are hard to move without KYC. This is the cost of having more freedom - some people will use it for bad things. But I believe that the good use cases are much more common than the bad ones.