Being better than SysV init is not something systemd has a monopoly on... Portability off Linux isn't a small concern for the Debian project as far as I know

Being better than SysV init is not something systemd has a monopoly on... Portability off Linux isn't a small concern for the Debian project as far as I know Red Hat related distros are very good distros based on systemd and are still available, it isn't necessary for Debian also to adopt systemd in order for people to use and enjoy it