There’s definitely a difference between knock out rugby and a full year of 6N, Rugby Championship/test matches, etc.
However, it’s probably worth remembering that England won by 6 points against a team which is coming off the back of being beaten by Portugal.
Ireland got beaten by NZ who got beaten by France who got beaten by SA who got beaten by Ireland*.
The right teams are going to end up in the final (I think!) but I really don’t think you can compare which stage each team goes out in the competition with how good they are in any meaningful way. At least not for this particular WC.
*which is crazy for all this to have happened in one tournament.