I wonder what makes you say this? In my (limited) anecdotal experience, I've noticed that Austrians seem to have far higher levels of English competency than Germans, for example.

Not sure how it’s graded but it is very rare to meet an Austrian who can’t speak basic English and kids in the cities these days are often practically bilingual!

I'm guessing Portugal must have improved a lot since I was there in 2019 and didn't have a great time trying to use English. I had better success rate with my extremely atrophied high school Spanish.

I’ve been to Portugal over 20 times in the last 10 years. In Lisbon and Porto, the Portuguese people speak English very well and most with an American accent. Foreigners who come to Portugal [1] and may work service jobs (a more recent phenomenon) may not speak English as well as the native population, while many of them still do still speak English well.

[1] https://en.m.wikipedia.org/wiki/Immigration_to_Portugal

Austria has a big tourist industry sector.

That's debatable, but there are some other howlers. The world's #1 tourist destination Thailand is near the bottom of pack 10 spots below Afghanistan, Finland is below Germany, Switzerland is below Serbia, and South Korea is almost 50 ranks above Japan.

The general population in Thailand has very limited English skills. As a tourist, you’ll encounter Thais whose jobs involve interacting with foreigners, and they can speak some English (not much). As for the rest of the population, english is practically non-existent ("hello", "good bye", and that's it).

are you sure you're not making that judgement just based on accents? As a German, Austrians and us tend to stand out a bit compared to Swedes or the Dutch in my experience when it comes to spoken English but otherwise proficiency is high, always seems like a bit of an outdated stereotype to me.

There is no way Hong Kong has moderate proficiency and German has high proficiency. It's a bullshit list.

This is coming from a German living in Hong Kong.