For me its the ‘Knock Code’ that LG had on their phones (I really wish LG still made at least the V series phones)
Basically there was a four-square area and you set up a sequence of where you would tap to unlock the phone. That set of squares was only shown when you set up the code
Then, to unlock your phone, you would tap those areas in the sequence you set up (even with the screen off).
Fingerprint readers are nice, but I really do miss the knock code
Edit: did find this article with a way to do the knock code, but if done wrong, could brick your phone I guess.
Plus, article is from 2014. When I looked at XDA’s info on it (they also being the developers) it looks like development on it is over, but individual modules may or may not still be supported by their devs
What sucks is it would be easily doable.
Before smartphones were big I had a Samsung Messager (I think) with a slide out keyboard). Why not? A slide out keyboard would be sweet, and then you could choose to enable the digital keyboard if you wanted.
Wonder if they make a phone case with a keyboard (they certainly make the bluetooth keyboards for phones)
Edit: did some looking. It looks like they used to make these in a way I was thinking, such as this one
They don’t seem to make them that way now (at least not for phones). I did run into a phone that has a new-ish phone that has a physical keyboard
I’ve seen such keyboard, packaged neatly into a folding case. Problem is the keyboard doesn’t have enough weight to support the phone so it becomes awkward trying to hold the weight of the phone with your fingers while typing.