chkconfig is a command that list services and its run levels on SysV. Now most distros are using systemd

[root@ns378707 config]# chkconfig --list

Note: This output shows SysV services only and does not include native
      systemd services. SysV configuration data might be overridden by native
      systemd configuration.

      If you want to list systemd services use 'systemctl list-unit-files'.
      To see services enabled on particular target use
      'systemctl list-dependencies [target]'.

netconsole     	0:off	1:off	2:off	3:off	4:off	5:off	6:off
network        	0:off	1:off	2:off	3:off	4:off	5:off	6:off
[root@ns378707 config]# 

Here only 2 services on this server as other services are managed by systemd.