Can the screen protector film only mask banking apps and notifications, but not the lock screen and homescreen?

It's a real, albeit minor, quality of life improvement for the phone screen to only become less-vibrant for a subset of content.

It’s clear that you haven’t really looked much into this. It’s per pixel.

Screen protectors also degrade light output

> Screen protectors also degrade light output

So does this function from Samsung. You can see in all the video demonstrations that the 'privacy' pixels are notably dimmer even head-on compared to normal pixels.

Not the same thing.

These pixels are dimmer by themselfs. They dont get muted by a layer on top of them.

This means way less energy usage therefore longer lasting battery at similar brightness!

Also these pixels can just go bright the moment you dont need this anymore, instantly making everything look good and bright again :)

This also degrades light output off angle. If you're showing someone a picture, you lose up to 50% of light output.

Sure, but presumably you wouldn't have the feature activated when you're showing someone something on your phone?

The Samsung masking tech can selectively mask parts of the screen. And it has configurability so it automatically is turned on only in certain apps and things like that. Because it dims the screen slightly (when you look at it straight on), just like a screen protector, it’s really useful that it can be customized in these ways. You get to keep the quality of the screen high to a much greater amount while still keeping your privacy.