> my shopping in Lidl or a Macbook are largely the same as what I would pay in Germany
The difference probably the Germans don't go buy at cheap stores like lidl. The easy way to do PPP is to go by how much people pay and not how cheap you can get something for, which gets you a much less accurate picture of how much it actually costs to live there.
That being aside, I mentioned Lidl cause they sell pretty much the same stuff in both countries. As for PPP, it's supposed to be based on a basket of goods, which is supposed to be as similar between two countries as possible.
Comparing lower quality products in country A to better ones in country B would tell you nothing.
The difference probably the Germans don't go buy at cheap stores like lidl. The easy way to do PPP is to go by how much people pay and not how cheap you can get something for, which gets you a much less accurate picture of how much it actually costs to live there.