Even if you feel the need to equate crypto-things to bonds, first you need to argue why buying, say, bitcoins can be argued as lending money to someone, which makes no sense whatsoever.

Cryptos are nothing more than speculation vehicle, and it's pretty obvious that they are massively used as a pump-and-dump scheme. The only point in time where cryptos played a relevant role as a currency was way back in the silk road times where cryptos were used with the expectation of laundring transactions. That usecases quickly went out the door ages ago.

https://blockfi.com/an-introduction-to-rehypothecation-with-...

So some people of reinvented fractional reserve banking. But now with the problem that it’s unregulated, unbackstopped by a lender of last resort and ultimately through rehypothecation you’ve virtually eliminated any advantage gained by using blockchain technology.

I'm sure bitcoin purist will hate it, but afaik there's a lot of btc being held at exchanges (e.g. coinbase).

Technically instead of holding BTC there, you could be holding cBTC (value in a coinbase btc deposit account) and coinbase could issue cBTC loans similar to banks.

(The issue is that there's no backstop like in the real world, where central bank can step in as lender of last resort to avoid bank runs)