The economy is in an objectively better position than when the GOP had office. The fault does lie with the dems, but if the economy was a concern as 38% of people said, then they would have voted democrat. The fact is they went too far right, floundered on their support of a genocide and failed to speak bluntly on matters such as healthcare outside of abortion.
I think people say the economy when asked as a catch all when they dont know what to say.
Again objectively better under biden