Your readers say they're too distracted to remember what they read, but that's a design problem, and it's yours.
Reading runs on reader psychology: they track what each sentence and the whole passage are about, hold old before new, and remember pictures over abstractions.
So the fixes are design choices: keep the topic consistent, order old-to-new, write flesh-and-blood characters, and stop narrating your own structure.
So is forgettable writing the reader's fault, or yours?
Yours — good writing is designed, not accidental.
Put the topic first and keep it consistent so the passage reads as one thing, lead each sentence with old information and end on new, turn abstractions into visual characters the memory can hold, and signpost sparingly instead of narrating your structure.
Design for how the reader's brain actually works, and your writing sticks.