While distinction between fictitious and arbitrary is technically correct, it's just pedantry which misses the actual point of the colloquialism. It's not that it doesn’t serve an exchange function, or that the dollars in your account are somehow illusory. It's an expression of frustration with how we have chosen as a society to treat economic institutions being treated as laws of nature, rather than as social construct which we ourselves have invented and therefore can revise at any time. As in much public discourse, the statement is a rebuke to the widespread habit of treating financial constraints as absolute barriers, beyond which no serious thought need be expended, and as an excuse for avoiding responsibility to address the underlying human issues. Correcting their metaphors ignores their argument. If the rules that govern human wealth are entirely of our own making, they can also be systematically changed whenever those rules no longer serve our common good.

Food is not being poisoned, what a crock of shit.

Meanwhile in the real world, there's literally a lawsuit against companies knowingly designing, marketing, and selling food products that are harmful and addictive.

Going on about how it’s being poisoned makes you sound anti-science or like someone trying to scare people into watching their paid content.

Again back in the real world, the history of US water pollution is unfortunately marked by numerous instances where industrial discharge, coupled with weak or failed regulation, has poisoned water supplies. Just a few examples which you could've trivially googled yourself