Apple care+ is approximately $40 per year plus another $80 for each repair due to "accidents" (unless it's the screen or back in which case it's $30)
That's a minimum cost of $138 per year if I don't suffer any malfunctions or accidents
The Fairphone is approximately $750 with at least 8 years of support. That's a minimum cost of $93.75 per year. That means that I'd have to crack my screen every 18 months or so for the iPhone to be more price competitive. Given that I've never cracked a screen that seems highly unlikely
For the battery I can replace it every 11 months and still spend less money with the Fairphone
Any other part breaking is a massive expense on the iPhone. Not including the screen, every spare part for the Fairphone is less than the service fee with apple care
If Fairphone ends up providing 10 years of support for the device, that just pushes the math even more in its favour
And all that is not even considering that the Fairphone comes with a 5 year warranty which would already cover any non-accident/wear+tear malfunctions