That's a bit of a childish remark. The celebrity stuff exists in every culture and every country, so there's nothing particular to monarchy in this regard. The British monarchy, is, of course, a castrated monarchy in the sense that it has little power, but it still functions as a unifying force for the UK. Some argue that monarchies are generally more tolerant than republics. Monarchy can be argued to be a more natural or default form of government in principle than republicanism because the monarch (the king) is a kind of paternal role. The dynastic component adds continuity, responsibility (you don't want your heir to bear the burden of your bad policies, do you?), and hedges against both short-term thinking (like we see among elected officials) and the dangers of meritocratic ambition ("I EARNED my power!" vs. "I am saddled with this responsibility to serve."). Of course, in practice, republicanism can become more attractive because of royal corruption and abuse of power, but the notion that republicanism is immune to these just because it takes different forms is absurd.
Remarks like "useless social fiction from antiquity" come across as uninformed, provincial snobbery motivated by some kind of superficial progressive mythology. There are forms of government that are objectively bad, others that are poorly suited to time and place, but the notion that the best form of government is the democratic republic, everywhere and in all times and places, is silly.