Marx was correct when he argued that economic democracy was necessary for political democracy. When the wealthy get to own the economy they have the entire country by the balls.
Funnily enough even Adam Smith warned about that even before capitalism went in full swing.
It definitely can be, for example art is very often hoarded as form of investment, and this can be a much lower-price form of the same, but not necessarily. I would say the more those things price is, the more chance for hoarding.
That is, economically. If you mean hoarding as in psychology probably it’s more depending on person, a lot of people i know including me were collecting more or less useless things but nobody i know went into true hoarding problem and most of those people at some point got bored and got rid of their collections. Other than above personal experience, idk.