This report gives the opinions of expert behaviourists and consultants on the reasons why some dogs may be aggressive towards people. Of the 215 experts who responded, some 74% argued that breed was either not at all important or only slightly important, whilst an overwhelming 86% believed it was due to the way that the dog was brought up by its owner.

https://committees.parliament.uk/writtenevidence/90096/html/

The law on dangerous dogs refers to specific breeds of dog as ‘dangerous’. However, we believe that breed-specific legislation ignores the most important factors that contribute to biting incidents – primarily anti-social behaviour by irresponsible dog owners who train their dogs to be aggressive or do not train their dogs adequately.

https://www.thekennelclub.org.uk/about-us/campaigns/dangerous-dogs-deed-not-breed/

https://www.theguardian.com/uk-news/2023/sep/11/banning-some-dog-breeds-in-the-uk-wont-stop-attacks-on-humans - study in comments

There is a ton of research on the issue.