As far as I know. nothing done in that video would be impossible on the latest kernel. Everything would compile and run comparably.

So long as the computer supports an instruction set from like the last 30 years you can run the latest kernel.

Here's a 133 Mhz Pentium running Gentoo with a very recent kernel.

I'd probably recommend something like Debian though unless you are really pushing the limits of the hardware.

If you have to ask, the benefits of another init system than systemd starts and stops at "you look smart." I like runit a lot and would even recommend Void Linux as a daily driver if that's your speed, but honestly anyone who actually was around before systemd knew how much sysvinit and co sucked.