Would you not consider any English players world class?
Sure, some didn't perform, it can happen to the very best. Messi didn't particularly shine in the 2010 world cup. He used to actually get criticised by Argentina fans at one point around that time until they started winning things. They used to say he's not the same player for Argentina as he was for Barcelona. Obviously it changed over time. But for a while he was accused of not turning up for a Argentina when it matterd, he didn't get the love there that others did for a time.
So I wouldn't be judging players being world class on whether they had poor tournament in a poorly managed team. It's like saying De Bruyne isn't world class because Belgium under performed many times as a team. We know he clearly is world class though.
Do you think Pep Guardiola would have Foden in his team as a 10, winning leagues and picking up player of the year if he didn't think he was world class. He would look like a fish out of water at City if he wasn't world class, yet he was player of the season. If you're not top notch, you don't cut it at City and get found out quickly, ask Mr Phillips.
There is some world class English players among some overhyped and some bang average ones. I don't think the England squad on paper is anywhere near as good as people say, but there's absolutely a few quality players who play and win things at the very top level and shine in top teams. A top champions league side would dick an modern international side, it would barely be competitive.
On the other hand, Andy Robertson is about the best player Scotland have produced in about 40 years and he's just slightly above average.