There's a couple of fallacies embedded here. For example, that there is a thorough and deep vetting process that is also impartial (vs being invested in denying benefits).

Also the assumption that an application that is denied == fraud. Programs are incredibly complex, and requirements are a moving target. I can imagine someone going to renew based on their understanding of the program, and inadvertently being flagged as fraud because some requirement changed (which in turn might have been incorrectly conveyed because the requirements are complex and even state staffers may not understand them all).

Some of this is down to the DOGE definition of "fraud, waste, abuse" as "anything we do not like." Using that definition, you can find fraud anywhere.