Just curious, how "left" and "right" anti-monopolist solutions might be different? I mean, naturally some "left anti-monopolist" people might be in favor of governments taking over industries, but presumably that's not what most of the people in question are advocating at the moment.
> But when the term [populist] is applied to people as diverse as Corbyn, Sanders, and AOC on the one side, and Orban, Farage, and Trump on the other, it's nonsensical without much more explanation.
I don't think so. It's essentially an accusation that they haven't thought through the hard issues: they're saying "We're going to achieve X", when in fact X is simply not possible given the current state of play (or perhaps, not possible without significant negative consequences, like erosion of human rights or setting up an economic or ecological disaster further down the road).
Boris Johnson's promise to conservatives that they'd be able to "make a deal" which allowed them to trade freely with Europe while not accepting immigrants from Europe was just a fantasy. A lot of populist "progressive" politicians make similar kinds of promises.