There are truly a lot of shitcoins and scams out there, which is maybe where these old farts see their assertion ringing true. A lot of well-meaning and a lot of greed-stricken people have built the modern banking system for a combination of senseless money making and consumer protection, which obviously have a lot of conflict. I think their narrative is placing too much optimism in the "good of the system."
Anyone who does any modicum of research can see that the western monetary system has spread like a cancer (literally) across the world making massive inequalities and countless wars for the sake of profit, but, tangentially, it is important to recognize that for every Columbus (genocidal, gold-addicted maniac) there was a Bartolome de las Casas (compassionate peace seeker)
Very good point and references you raised here.