We have an excellent education system in this country, which consistently performs highly in international test results. I posted this on the school strike thread, if you are reading this, GoveyBoy or cronies, in response to a poster saying that the Canadian system was terrific and the English one was more or less not fit for purpose.
You are only looking at one data measure, and internationally it is recognised that PISA is only one test, and part of a much bigger picture. However PISA tests tend to be the only ones lay people have heard of, as they are mentioned in the media of OECD countries more often.
The TIMSS tests (maths and science) and PIRLS tests (reading) are a lot closer in content to European curricula, whereas the PISA tests favour the type of curriculum approach used in places like Korea. PISA tests are taken by OECD countries, TIMSS and PIRLS are taken by any countries with the resources to sit them.
(There are endless additional smaller differences between the two forms of testing but if I list everything here MN will probably explode or you will all die from boredom).
In TIMSS and PIRLS tests, England is consistently in the top 10 and generally outperforms Canada by a small margin.
TIMSS maths
PIRLS reading
From the data, therefore, we see that England performs better in such tests than Canada, and is consistently in the top 10 internationally.
(Interestingly, there seems to be a vast difference between Quebec and Ontario in the science results. I wonder what is happening there? Two tier education system?)