Variable interest rate loans are very tightly regulated. You could argue 'not tightly enough', but personal loans in general are probably one of the most tightly regulated industries there is.

If they're legal at all they're probably not tightly regulated enough. They're certainly not well regulated enough now, you have morons on YouTube telling each other to buy investment properties with HELOC loans. IMO that's a far larger issue than people blowing money on worthless crypto tokens.