Netflix streams are usually so compressed that there is a noticeable improvement if you use 4K over 1080p. What you're actually comparing is "blurry 4K" to "blurry 1080p".
And that's if they give you 1080p. I cancelled Netflix because they rolled out price hikes and yet even dominant platforms like Chrome on Windows only get blurry 720p which is completely unacceptable these days:
