There are 2 main reasons I think Backgrounds trip up artists.
1- They have years of experience developing shorthand for characters but have none for BGs
2- Characters are fairly narrow. "Backgrounds" can mean everything else in the world.

A great way to circumvent both of these trip ups is to
-Choose a narrower goal than "learning to paint BGs" EX: Learning to paint interior fantasy living space scenes
-Focus on developing shorthand for things common in your focus and study the shorthand others have created

Example: my shorthand for glass is a combination of smudging whats behind it and creating boxy highlights with a motion blur.

Second example: my shorthand for plants is a repetitive silhouette shape with color jitter grain + a couple of painted leaves here and there.

These shorthands all come together to form an artists "style" ultimately. For an artist who's only focused on characters, painting each new object in a background can feel like starting from scratch because they haven't gone thru the process of creating shorthands yet.

It gets much, much easier over time. Once you go through the process a bit, you get the hang of it! I used to be scared of environments, and now I love them.