Pretty sure most people didn't buy BTC at $20K, which it never actually even reached. It didn't spend much time above $19K either.
If you look at the charts, it didn't even spend much time above $16K or so.
Most people lost huge sums of money because they invested in alts which are like 90% red. Look at Ripple or Dentacoin or what-not.
I assume most invested at like $12K and its half now, so its only a 50% loss. However the alts are a different story.
People definitely got crashed by alts, that's true. That's what happens in bear markets; alts are much more brutal. On the flip side, they're much more profitable during alt season. It's all about recognizing where we are in the cycle.
Nonetheless, by any conventional standards, the losses from $19K or even $12K are massive. People used to investing in stocks and gold, etc aren't used to this magnitude of loss so quickly.