Fraud is only a small part of the problem. No open data, poorly described methodology so reproductions sometimes aren't even possible, too little funding for reproductions, p-hacking, no incentives to publish negative results, journals incentivized to publish sensational results to increase their impact factor even though sensational results are likely false thus perpetuating misinformation. These are the main drivers.

It’s more that a system should not allow a single fraud to shape its understanding and its policy. Assume fraud exists.