After executing the service list command, you can see that many system services have no interfaces？
# service list | grep '\[\]'
5 app_binding: []
24 network_time_update_service: []
25 runtime: []
26 diskstats: []
39 DockObserver: []
43 devicestoragemonitor: []
63 testharness: []
70 pinner: []
80 device_config: []
81 settings: []
88 looper_stats: []
89 binder_calls_stats: []
93 battery: []
102 cpuinfo: []
103 dbinfo: []
104 gfxinfo: []
105 meminfo: []
Why is there such a system service? If they do not use the binder, how do they communicate with other processes？
Services which do not show an interface to service list did not respond to the INTERFACE_TRANSACTION ('_NTF', or 1598968902). There are two possible reasons for that:
A) The service has no interface, so it responds to the default transactions only (you can find a list of those transactions here. Normally, this would be the DUMP_TRANSACTION (_DMP), which is used by /system/bin/dumpsys, and in rare cases SHELL_COMMAND_TRANSACTION (_CMD), for /system/bin/cmd.
B) The service declines answering _NTF, because you are not permitted to, or you couldn't get a handle to them. To try this, su to an isolated app (su 90000) and try service list - only services which allow_isolated (activity, webviewupdate and maybe one more) will respond. But even as AID shell, vold for example won't answer.
In the above, you were doing this as root, so it's A - and they all are meant to be dump sys only.