This is one aspect which I'm slightly surprised isn't discussed more.
As many of these companies were failing one by one, I noticed that I'd not heard of most of them.
It comes with the benefit of hindsight, but it seems pretty obvious there was insufficient regulation in place as almost any Tom, Dick or Harry could start up an energy supply business, immediately undercutting the legacy suppliers and hoovering up new customers quickly.
They were assisted by the likes of Martin Lewis/MSE and various price comparison sites who had a significant vested interest in getting people to move suppliers as they earned a sizeable affiliate kickback each time they introduced a new customer to an energy supplier.
So we had the situation where there seemed to relatively low barriers to entry, and stimulated demand encouraging new entrants to come to market.
It's now all collapsed, leaving everyone to pay the price.
I don't wish to be banned.