> half of these European countries had absolutely nothing exceptional going on mortality wise between 2020 and June 2021

That's not how I read it. First, all except Norway, Finland, Estonia, Denmark had at least +20% in 2020. Second, it's the peak that the graph plots so you cannot use it to take conclusions over the whole year. All the graph can tell you is how hard the country was hit by the spring 2021 wave compared to 2020.