Sharing is invite or link-based. Though you can see the Team, folder path and filename in the resulting share link.

The default sharing setting for our organization is "Specific people" Most Teams have "Anyone" (Public) sharing enabled as an option.

Either select Share (best for inviting existing users to a folder or document) or Copy Link Both allow you to select a sharing level, "Anyone" through "People you choose".

You can also set the sharing permissions from the default View to Edit or block direct downloads.

The "Anyone" setting in addition gives options for setting an expiry time or a password.

If the expiry is not used, it may be difficult to tell which files have been shared with whom. You can only see the sharing settings by selecting the Share/Copy link context menu and noting both the user icons as well as links listed below it.

To avoid having to manually create links to every document to publish, you may want to create a "Public Share" folder, create an "Anyone" link from it with no expiry and use that in website or materials. This way you can drop files into this public folder and they become public for anyone with that link automatically. The downside is they can browse all other documents in that folder. But these already should be public.

It may also be fewer steps to invite a guest (such as temporary collaborator) to the Team and add them to a "Shared channel" directly.