The point is a little different. The Product Owner should encourage the others to insert new items, so that the PO does not become a bottleneck to the process. Imagine working with multiple teams, if the PO is the only one writing the items, it will be counterproductive.

In the end of the day, the PO is accountable for the backlog. So mentoring the stakeholders how to write better PBIs also helps the PO to thrive.

The Product Owner should for sure evaluate what matters and what doesn't. Keeping items that doesn't matter is also counterproductive.

What I encourage to do is to collaborate more, teach how to fish instead of giving the fish. I've seen many scenarios where the Product Owner becomes a bottleneck because of trying to centralize many parts of the processes.