[Assist] Why does community repo lag behind Arch while extra doesn't?

[dllud]

Hi!

I am having issues with incompatible package versions between the
'extra' and 'community' repos.

On extra there is qt5 5.12.0, while the qt5-styleplugins package from
community is still at version 5.0.0.20170311-8, which was built for a
previous qt5 version and is now incompatible. The fixed qt5-styleplugins
version (5.0.0.20170311-9) was put into Arch's community repo on the
same day as the qt5 upgrade (2018-12-10) but still didn't made it into
Parabola

What causes this lag?

I am using the default /etc/pacman.d/mirrorlist that points to
https://redirector.parabola.nu/$repo/os/$arch and
https://repomirror.parabola.nu/$repo/os/$arch

Regards,
dllud