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.
The 50 years was just an arbitrary number for my example - one could even start pondering the same question in regards to 1,2,5,etc years.
Thank again for informing me of the importance of storing my 'keys', but my intention behind this question was not to imply that this is what my intentions were in any way - I was just curious as to what would actually happen.