This ranking was made a year before an actual pandemic and they had more misses than hits, and understanding why may help with other predictions about the future. At least the ones involving human actions.
Same with the UK: the response from their scientific community has been absolutely fantastic. But when Boris Johnson simply didn't want to lock down and couldn't make up his mind until too late that didn't count for much. Also he fucked up the test-trace-isolate system for ideological reasons.
Sweden + Denmark were rated as more prepared than Norway, which could well be true, but Sweden chose the UK approach (for no sane reason) and has paid the price.
In all of these cases the problem is not lack of ability to handle the pandemic, but a political lack of will to do it.