30 - 50 years is a very long time to go on and expect any technology to still function, let alone a ledger wallet.

I'm sure that theoretically speaking there's a lifespan for the circuit board. Depending on the quality of the chip it is possible to reach the lifespan you want, but it's really a stretch.

Store your keys in a paper wallet and keep it in your home's safe, that's years more efficient than storing the device and finding out after 30 years that it won't boot.