Let's offroad / mountain bike / mtb / ride dirt

Then we have hub gear product lifespan, they are not all rated for heavy abuse.

I reckon we put 8000+ miles through a SRAM Nexus, on a bike weighing an average of 150kg, through 5 winters. We never serviced it and all that was ever changed was the rear axle when the threads stripped.

Also, [fat] bikes look best without derailleurs and cassettes cluttering them up.