Unfortunately I've found the screens on the older ones to be quite fragile (at least the 4th gen)

I went through a phase of buying used 4th gen ones off ebay so that I could have physical buttons to turn the page, but within a couple of months they would always end up up with cracked screens

They would be stored in my bag next to my laptop (and in a case) but at some point I would end up pulling it out to read and find a cracked screen

I think I went through 4 of them before I called it quits, my current paperwhite is still going strong (just no buttons sadly)