How did you go through six? I still rock my first and almost a decade old kindle
Working in machine shops; I often had cycle time to read. Drops killed most of them. I had a few mysteriously die. When I would open them up, there was board and frame corrosion. Metal working fluids and fine metal chips are hell on electronics.
Dropped a few in the bathtub. Current kindle has been dropped in the bath, but survived. It may die due to corrosion. Battery is getting weak anyhow.
For years, I didn’t use a cover. I now have one of the official Amazon covers and have gotten better longevity on my former and current kindles. My case has a crack in it due to a drop.
I consider them a consumable, they’re cheap compared to the knowledge and pleasure they give me.
When you use them heavily some of the incremental improvements are nice to have. I swapped my mid 2010s Nook for an ~8in Boox 3y ago or so and it was a huge upgrade.
