Fairphone is a great product and I have a lot of respect for them trying to do what they're doing. But the sad brutal reality is that it's a very niche in the grand scheme of things and won't change things. I equate it a bit to "The year of the Linux Desktop" happening making everything better.
We have to be honest with ourselves about this, recognise how the deck is stacked against us and respond accordingly.
Linux won though :) "the year of the Linux Desktop" is a joke that started over two decades ago to dismiss Linux and OSS as a delusion of a few nerds but now we have Android devices everywhere, every server on earth using it, supercomputers/HPC clusters, game consoles, and even on desktop it keeps growing. Those who were in the FLOSS community back in the late 90s and early 00s probably remember how most people literally laughed at you and would call you crazy just for believing that things could be different.
The idea of a phone that can have its battery easily replaced is several orders of magnitude less crazy in my opinion.
We have to be honest with ourselves about this, recognise how the deck is stacked against us and respond accordingly.