Let me tell you my story of a closely-related mobile device and its relative longevity.
I bought a first-gen iPad Pro, the 12.9” model, as an open box from a reputable online retailer (not Amazon) in 1/2016. I use it semi-professionally, and the battery finally failed a year ago. I called my local Apple Store in a panic, and I took it in. The warranty was long expired, but they gave me the option of a battery replacement for $100… I took it. The shocker was, they didn’t actually replace the battery… they had a mint-condition refurb in the back, of exactly the same hardware config, even down to the correct color! They managed to wipe my old device after transferring everything “mission critical”… I had a local backup for everything else at home. The refurb has been perfect ever since, and I’ll keep it until they end security updates (no end in sight). Again, all that for a flat fee of $100. No blemishes, absolutely as-new. This as close to BIFL I’ve ever gotten with a complex battery-powered electronic device.