It was aimed at you, but I see what you're saying now.
It's interesting how different people see different things in data.
https://tradingeconomics.com/europea...gdp-per-capita
If you set it to "max" it shows the EU GDP per capita since the early 60s. To me it shows a steady unchanging rate of growth up to about 2007 then a sharp decline followed by a return to a similar rate of growth. Where's the slowing you see post-Maastricht?