It was possible to have < 5 second boot times in 2008 https://lwn.net/Articles/299483/
I'd be interested to know if the systemd boot process (which can be 2 seconds or quicker) has enough advantages to make the other changes worth it.
See this prior NH submission [1], and inthe G+ post he mentions fairly early on why it's important to be very quick in the boot process, and how DHCP figures into that. (TL;DR using VM containers that can normally boot within 100 ms, getting the DHCP server to respond within 50 ms means on-demand container spin-up for a specific request is possible)
rc.conf was removed in Archlinux as a final step of the path to systemd and became obsolete when sysvinit became obsolete, not prior.
The removal of rc.conf was the final step, but they had been dismantling rc.conf piece by piece for years prior, even before systemd was released.
When I first used Arch in 2006, rc.conf held a lot of configuration. From what I understand, it held even more configuration options prior to that. Since that time and until the removal of rc.conf, there was a steady removal of features from rc.conf.
> I mean what's the point installing Arch if there is no very elegant and beautiful rc.conf?
rc.conf removal had nothing to do with systemd, I think. And was removed prior.
> What is that killer feature that Arch offers, apart from being rolling release?
Vanilla upstream packages.