But void and thousands of others decided it was too much of pain for no "perceivable" gains.
It goes along with decisions such as elogind, dropping ck gksu, and adopting zstd (like artix).

Some dummies will follow trends even beyond a cliff.

eric wrotezstd: before with xz the JWM flavor had a size of 700M, with zstd 1.2G.... what is the gain? faster at installation? yes but double at download time and size on the disk.

Recently I found an old installation on this old backup disk that hasn't been used for more than 2y. Just for fun I decided to upgrade it to see the difficulties, and one thing I noticed was a near 15% growth in size. I don't think it is all arch's zstd fault, I think software is growing, in fluff, but growing. linux-firmware for example has nearly doubled in size in 1 year. Since I don't use anything new I have been using a pkg from a year ago and then placing it in ignore, if I use it at all.

There was also a small artix installation in there, so I decided to do that one too. Near impossible. Their old pacman doesn't know what to do with zstd, but even when you do install externally the zstd pkg if it is not the right version for the transition it is useless. So then I tried to unpack some pkgs with zstd and compress them again with xz so it can install them with pacman -U. Then pacman itself wouldn't work with the correct glibc which is not the current version, ... I finally gave up and erased it all. The earliest versions of zstd were packaged with xz ofcourse, but I never thought of this much before :)

Arch justified the speed differential of xz and zstd using an xz option of -T1. When xz is used with a single thread while zstd is multithreading, the speed difference is as enormous as your machine's difference with one of a single thread/processor. When you use the better option the speed difference is small, but sizewise xz always wins. When size becomes nearly as good as xz then zstd is not very fast and uses tons of ram.

Arch doesn't give a damn about their mirrors growing in size or their mirrors growing in bandwidth. Bandwidth and disk size is FREE for "free facebook software" pkgs. But user experience is "positive", unless they have a question that tends to sound like criticism towards arch, then they say go kill yourself, we are arch.