Very interesting post. I know ETFs exist, but I didn't pay much attention to them.
After reading your post, I think I should read more about them, and I'll tell you why.
In my country, buying and selling cryptocurrencies is taxed. But if you buy a CEDEAR (it's the equivalent of an ADR in the US) and then sell it, individuals don't pay tax on the gains (the transaction is exempt).
So, I think it's an excellent way to invest.