With depressing regularity someone will suggest that deleting the shader cache is a cure-all for graphics anomalies and should be a regular part of X-Plane housekeeping.
The short answer is “No it isn’t” and “No it shouldn’t be”.
Don’t bother to delete the shader cache – it won’t fix anything
The long answer is buried in a long-buried discussion conducted over a year ago on X-Plane.org. Go to this link – it’s page 3 of a long thread about Public Beta 12.2.0-b4. Read the explanations (various posts) written by @JustSid (Sidney Just – Laminar’s graphics technical guru) – who is really the ultimate authority on this matter.