⚡ Quick Fix (TL;DR)

The Culprit: A background image alone doesn't guarantee enough contrast for text placed on top of it.

The Fix: Add a translucent dark layer as part of the background treatment, darkening the image enough for light text to stay readable. Depends on how the rest of the section's background is structured.

.my-section {
  background-color: rgba(0, 0, 0, 0.4);
}