Perhaps it’s not capitalism that’s the problem but the unboundedness of the greed of a few, with respect to the other needs of humanity.
Also Adam Smith implied that unbounded avarice is irrational and disruptive to society.
The assumption is that morality survives grotesque wealth accumulation, we see many examples proving otherwise
"unboundedness of the greed of a few"
Lots of people claim "greed", but the stereotypical Tech billionaire doesn't simply roll around in gold like Scrooge McDuck, doing nothing and demanding more. They invest and reinvest it into new enterprises.
Of all the ways of dealing with massive wealth, this is probably the second least disruptive one. (The first one would be just giving it to honorable causes.)
Capitalism is the only known system that aligns natural, normal individual greed with the benefit and advancement of the society.
"Capitalism is the problem" by itself is like saying "unix operating systems are a problem". There are so many flavours, so many parameters (laws, tax, etc.) that I do not see value in generalizations.
I think morality is quite hard to define and any system should take into account unboundedness of some human attributes (being greed, stupidy or other) in some humans.