For a "similar" approach, I would opt for a slackware or a gentoo.
I understand that some people would like to keep Arch 32 bit for their use cases. But as any open source project, the developer are mostly working on it on their spare time, you can not force them to work on anything. Having followed a little bit the discussion on the mailing list [1], I don't remember having seen a lot of objection among the developers. Also, they encourage the creation of a community around i686 [2]:
However, as there is still some interest in keeping i686 alive, we would like to encourage the community to make it happen with our guidance. The arch-ports mailing list and #archlinux-ports IRC channel on Freenode will be used for further coordination.
So if there are people willing to do the job, Arch will still be usable on 1686.
Debian testing is similar in "rollingness", Slackware and Alpine are similar in the sense of "no frills". OpenBSD is a good non-Linux choice to try out.
A six-year-old 32-bit processor (e.g. an Atom in an EeePC 901 or HP Mini 311c) is more than capable of running a modern desktop system.