AR49: What is the point of a Global Depository Receipt?

So this is my understanding of depository receipts: they are controlled by banks and used to simplify foreign investment.

So for an American Depository Receip t, let’s say we have a Japanese company like Nissan. Nissan wants to raise as much capital as possible so they court American investors. A US-based bank such as Wells Fargo agrees to custody 10,000,000 Nissan shares. Wells Fargo then sells ADRS to Average Joe in the USA. Average Joe doesn’t have to worry about currency exchanges or paperwork, but his investment is subject to exchange rates because Nissan earns their money in yen. When the Yen is strong, Joe’s investment is strong.

Now for a Global Depository Receipt : Same as above but now a Japanese based bank buys the Nissan shares, and the Japanese bank is the one marketing Nissan shares (in the form of the GDR) to Average Joe, who lives in the USA. If my understanding is correct, I don’t see why Joe simply can’t purchase Nissan shares directly through his Charles Schwab account, or purchase the ADR hosted by Wells Fargo. What was the point of the GDR?