I only installed xfce4-screensaver a few days ago (2025-02-07) to find out why it was blanking display after 5 minutes instead of time set in power-manager
I still have light-locker installed, but it has not been updated in the last few years
[2022-03-12T18:41:50+0000] [ALPM] upgraded light-locker (1.9.0-4 → 1.9.0-5)
light-locker was last included on manjaro-xfce-23.0.4-231015-linux65.iso
and replaced with xfce4-screensaver on manjaro-xfce-23.1.0-231215-linux66.iso
[xfce] use xfce4-screensaver (2ffe8171) · Commits · Profiles & Settings / iso-profiles · GitLab
There may be many users that installed Manjaro XFCE before Dec 2023 still using light-locker