Pretty much yeah. The price for groceries or bills don't differ too much between EU countries at this point, but the price of real estate and having your own place either paid off or secured at a good price and a good rate makes the biggest difference.
Earning 50% more before tax somewhere else is not a good deal if there's 200 people fighting for every moldy 20sqm apartment that hasn't seen a renovation in 50 years, and you also no real chance of affording to buy something decent in that area.
Real estate is messed up in EU at the moment. Far too expensive considering the wages and rates.
cost of living is highly relevant when you compare salary data because it's one of the primary factors that determines the cost of labor.
If you pay a Berlin salary in SF nobody's gonna show up because that doesn't cover your apartment rent. It tells you little about how much you effectively pocket. If you want to get some use out of this data you need to adjust it for purchasing power.
You’re right. Which is why it’s great that this link was posted. You can now take this available data and combine it with you understanding of the CoL on the various locations. Otherwise you’d only have a feel for the CoL.