To play devil's advocate, the traditional answer from socdems or commies to 1 and/or 3 is that concentration of capital is necessary for the modern industrial society.

Yes, of course. But there might be middle way: have very restricted and controlled events of capital accumulation. And shed lots of light (i.e. transparency) on them. And force them to not outlive some duration. And so forth.

But the real discussion is: how much industrial society do we need? One ipad every year, really?

Of course industrial society has some benefits: it allows use to be communicating here, for instance. And, of course, pre-industrial societies were in many cases an inequality disaster.

Then this discussion becomes extra-special if we thrown in the ongoing and increasing resource constriction of the next decades. It puts the feasibility of industrial society (especially at current levels) also on discussion.