Elastic Agent vs System integration

In my ELK stack deployment I have for most agent policies the System integration set with the "Collect metrics from System instances" enabled as can be seen below:

Recently I saw that there is a setting to enable logs and metrics for all agents in the group policy. That setting is in the general settings for the group policy:

So it states that will create the Elastic Agent integration (elastic_agent dataset) with the default namespace above.

So how is it different from collecting logs and metrics from the System integration and which is superior or best to use?
I don't want to have duplicate information and I tend to believe that the data in Elastic Agent integration is just that.

Lastly when I checked the data I saw that the underneath modules collecting the data were the filebeat, metricbeat, etc modules.

Any thoughts on this? Thanks in advance

These collect logs and metrics specific for the Elastic Agent.

For example, the system integration will get logs and metrics for your system, but not the specific logs and metrics of the elastic agent applications.

Imagine that you have a web server running NGINX, if you use just the system integrations, you will not get specific metrics and logs for NGINX, just for the system.

If you add the NGINX integration you then get the logs and metrics for the NGINX application.

It is the same thing with the Elastic Agent integration.