Why is cron not in the Provides field?

Installing systemd-cron removes ubuntu-standard, which has a dependency to cron.

# apt show systemd-cron
Package: systemd-cron
Version: 1.5.12-1
[...]
Provides: anacron, cron-daemon
[...]
Conflicts: anacron, cron-daemon
Replaces: anacron, cron
[...]

# apt show ubuntu-standard
Package: ubuntu-standard
Version: 1.407
[...]
Depends: busybox-static, cpio, cron, dmidecode, dnsutils, dosfstools, ed, file, ftp, hdparm, info, iptables, language-selector-common, libpam-systemd, logrotate, lshw, lsof, ltrace, man-db, mime-support, parted, pciutils, popularity-contest, psmisc, rsync, strace, time, usbutils, wget
[...]

Is there a reason to why cron is not in the Provides field?