If they really manage to support this device for 10 years, that's $75 per year, which I think is relatively cheap
My use-case for a phone does not need a lot of processing power. I use it for messaging, checking emails, watch a bit of YouTube, and catch up on the news. I feel reasonably confident that it will be able to perform those tasks 8-10 years down the line
On top of that I also appreciate that I can buy a device that is sourced with consideration for workers and the environment. It's never good for the environment to produce new devices, but the option to limit the impact is important to me