@webology there is no need to wait until its too late and complicated to act
Have, e.g. a progressive corporate tax that scales with market share and dis-incentivises gigantism and conglomerates
As a rule of thumb, you should never have any entity control more than 10% of anything. Thats how you preempt bad scenarios, diversify risks from known and unknown factors.
Society gains nothing from megacorps (economies of scale are already available at much smaller level). They are just vampires.