Chelsea’s best performances were against Liverpool, Arsenal, Spurs and Man City but usually when they’ve come against a lesser team that’s going to be more defensive and less full on attack they’ve struggled such as West Ham, Brentford, Villa and Newcastle
But they’re not worse opponents if they’re beating Chelsea. You can read whatever stats you want or look at how much has been spent, what matters is the result on the pitch. If a team, no matter where they are in the table beats another team, they were better than that team because they won and winning is what the game is about.