I worked in fraud prevention for years and device fingerprinting didn't stop fraud, but it reduced it by upping the up the cost. It is not hard to circumvent fingerprinting, but it still takes a non-zero amount of effort on behalf of the fraudster. Device fingerprints helped us identify and block or prevent a lot of low effort fraud and abuse on various platforms.

If it didn't, why do you think every captcha solution uses it? It doesn't have to be 100% effective to be useful.