Practical benchmark
A good score is the one that supports your specific pathway cutoff. Many applicants target CLB 9 because language points can increase significantly at that level.
Target by profile
If your CRS is already close, CLB 7-8 may still be sufficient depending on draw dynamics. If your profile is borderline, CLB 9+ can materially improve ranking.
Plan smart
Use your weakest section as leverage. Improving one lagging module from CLB 7 to CLB 9 can matter more than polishing sections that are already high.