Portable computing machines peaked in the 90s and since then have suffered from the introduction of new technologies that severely decreased their reliability and longevity.

Flash memory

Before this, you used battery-backed RAM and an "AAs + coin cell" approach to keep it alive while swapping batteries. RAM is an unfussy technology without lifetime concerns. All necessary system software is in ROM, is well-debugged (because it can't be updated), and resetting to factory state is quite simple: clear RAM, boot from ROM.

After: You must now patch your firmware to whatever version the community/homebrewers support. Once you use up all your write cycles, machine loses its mind or bricks itself.

Li-ion batteries

Before this, you used standardized modular batteries like AAs or coin cells. When a new battery technology comes out (like rechargeables or NiMH's), upgrades are automatic and backwards-compatible. Battery life is limited only by the number of spare cells you bring.

After: Batteries are custom to the machine and often go out of production along with it. Batteries may be sealed inside and inaccessible without specialized tools.

There are many machines I would collect if not for these poison pill techs.