Polling on particular issues can be shifted by propaganda, so this isn’t a particularly strong argument against the idea.
Although, I’m not sure what propaganda really means in this context anyway, I mean, “the economy” is a pretty abstract thing so people engage with it mostly through reporting of various sorts. The decision of what aspects of the economy to focus on could be seen as propaganda.
The admin plays in a global economy which is ridiculously complex, so there’s always room for it to be doing as well as possible when my guy is in charge, underperform expectations when the bad guy is in charge.