"accidentally end up in a screenshot" --- how often do you even take a screenshot on a phone, much less accidentally?
Consider that people use their phones differently than you. I take screenshots on a daily basis, accidental ones at least once a week. Usually it's just the lock screen though.
I take them constantly. Not even sure how. I think it means I am “of a certain age” these days.
Now get off my lawn.
i take many screenshots, but about half of them are accidental (somehow it recognizes the "tap three times" gesture whenever it feels about it)
Almost daily on my iPhone.
The side button (https://support.apple.com/en-gb/guide/iphone/iph7d116e557/io...) is on the exact opposite of the volume up button. Pressing the side button to shut down and lock the screen is something I do a lot. Press button (2) with the thumb and you will see that it is very natural to have your index or middle finger resting where the volume buttons are.
And occasionally I press hard enough with my thumb that the finger on the perpendicular side of the phone presses the volume up button and whoops I have taken a screen shot instead.
That said. I do consider this "feature" an abuse of privacy API:s, and I also often get annoyed that I cannot take screen shots of my bank app to for example send account information, or confirm a transaction, or report a graphical bug to the developers at the bank.