Casual retail investors can't get over the fact one BTC is so much money and doesn't return anything. When they see other coins are cheap and give 10% or 20% in "interest", and can rise in price like crazy.
Of course it always ends in tears...
From what I read Luna had limits on what could be printed in a time period, but when things started going wrong they immediately changed the limits, and some hours later they were printing billions of coins a minute, then dozens of billions, it was totally absurd.
Then thousands of trillions.