I am not because I live in a pretty conservative area. So I try to get some leftist points through to coworkers without opening myself up to the ridicule of just being a “commy degenerate” in their eyes. So I think I can get through to them better without outting myself as a Marxist.
The law of supply and demand describes markets very well so long as there is sufficient competition.
It turns out that one of the only markets where that is consistently true is the labor market. So whenever some cultist of the free market goes on about how supply and demand will regulate everything without needing any intervention, you can tell them that the law of supply and demand is exactly why it is inevitable that the people who work for a living and sell their labor on the market as a commodity will always see the price of their labor (i.e. wages) consistently get pushed down further and further to basic subsistence, while simultaneously needing to work longer and harder.
The whole selling point about how free market competition is what allows you to buy the best possible products at the best possible prices is something that applies most significantly to the ownership class who buys and sells our labor.