At least in CS/ML there needs to be a “code or it didn’t happen”. Why? Papers are ambiguous. Even if they have mathematical formulas, not all components are defined.
Peer replication in these fields is an easy low hanging fruit that could set an example for other fields of science.
But your run of the mill niche topic will not have the dollars behind it to replicate everyones research.just because CS/AI research is very convenient to replicate does not mean this can be extended to all research being done.
That is exactly why peer review exists to weed out the implausible and low effort/relevance work. It is not fraud proof because it was not designed to be.
This should be standard now, in the age of GitHub, GitLab, et al. If a paper discusses an implementation, but doesn't provide code, it is probably BS.