The investors themselves aren't overleveraged, but the ETFs they're purchasing are. Your link specifically refers to the amount of leverage offered to individual investors
So, for example, that regulation does not prevent me from buying an overleveraged ETF, but only from overleveraged my own account (whether it be buying these ETFs or a share of coca-cola)
Yes, but a directly levered position and an indirectly levered position, for all but Talebian wet dream scenarios, have the same exact risk profile.
Levered notes are regulatory arbitrage and are not materially safer investments levering up on one's own. In fact, the investor is probably better served by the latter due to lower fees.
So, for example, that regulation does not prevent me from buying an overleveraged ETF, but only from overleveraged my own account (whether it be buying these ETFs or a share of coca-cola)