need it? Of course not, but we don't need bikes
I do really, otherwise I'd spend a lot of time walking. The thing is, I used to have a bike with 21 gears which worked really well. Then I had one with 24 gears, which was OK too. Then I ended up with one with 27 gears which was worse in every way except for racing on, and was considerably more expensive. Now I'm going to end up with one which has 20 gears which are as good for racing on as the 27 were but which are in all other respects a total ball-ache. And it's going to cost even more.
I don't want to turn into sfb, but from the point of view of the enthusiast rather than the racer it's tricky seeing real advantages, but SLX (which is hardly a race-head's groupset) will be converted, ye say. 🙂