Genuinely curious: what issues are you specifically referring to?
> BTC & ETH aren't deflationary as much as they are predictable in their money supply.
See this is another crypto myth. So yes Bitcoin is limited to ~21M coins theoretically but we don't actually know what the limit is because wallets have gotten lost and will continue to be lost. Second, a lot of crypto people don't seem to understand the impact of derivatives to effectively increase the supply and thus bring about all the problems crypto advocates say crypto doesn't have.
I mean look at GameStop. There are a fixed number of shares on the market (buybacks and issuing new shares notwithstanding). Yet derivatives created a situation where there simply weren't enough outstanding shares to cover short interest. Taken to its extreme this would mean those shares would have infinite value.
What really undid the subprime mortgage market (other than the fraudulent ratings for which no one went to jail and they absolutely should have) was all the derivatives on top of actual mortgages. I forget the exact number but it was something like a factor of 10-20 (meaning $10-20 in derivatives for each $1 of a mortgage).
The exact same thing can (and will) happen to crypto. That's why fixed supply is a myth.