Yeah, I’ve done something similar with ~120 wifi bulbs for a light show that responded to music and that worked fairly well but I doubt it would have worked with more than a few hundred.

If they were hardwired yes, but zigbee with millions of bulbs?

The average credit card interest rate is 25%. Yes people shouldn’t borrow money they can’t pay back. However that doesn’t change the fact that interest rates on credit cards are wildly high and entrap people in a loop of only paying the interest off. Bankruptcy is their only hope of escape from that debt cycle.