Is it impossible to improve the quality anymore?

I’ve seen countless Z banding and wobble posts on the Bambulab forum.
I also tried to implement the solution in the post

1. Replace the Hot End Set
2. Normal acceleration 10000 → 3000 / Outer wall acceleration 5000 → 2000
3. External wall speed 50
4. Internal/Wall Filling Overlap 15% → -5%
5. Internal fill Grid → Gyroid
6. Number of outer walls 2 → 3
7. Slow printing down for better layer cooling option off
8. Loosen the extruder tension screw as much as possible

I’ve done a lot of things, but I couldn’t get rid of the pattern that occurs when the lights are illuminated up or down.

Is this type of problem that FDM printers can’t solve forever?
The filaments used are Bambulab PLA Basic Black and flow rate and k value calibrated all done.