I only found out about Apple's backtapping yesterday, which I've mapped to the window switcher and camera. It's basically worthless; won't work reliably if even a smidgeon of your skin is in contact with the screen, which is hard to avoid given the lack of bezels. Also impossible to pull off one handed. Found myself wishing for a squeeze action exactly like this, without realizing it's already a thing. Even one extra mappable button would be amazing, but it's Apple we're talking about here.
my Pixel 3 also has that... best phone I ever bought for $70, a couple of years ago (used)... it takes a screenshot whenever I squeeze it.