Comparing Workflow with Content Moderation+Workflows in core

In fact, core now has 2 new experimental modules:

• Workflows is a new experimental module in core
• Content Moderation is a new experimental module in core

Workflows is mostly a programming interface. Indeed, Workflow and Workflows are now duplicates in that respect.
Content moderation mostly adds an environment to prepare content, and have a reviewing cycle, before releasing a web page.
Workflow adds a Field type to ANY entity_type, and is agnostic for the type of entity/content. It an be used e.g. for your locations/stores 'open', 'closed', 'temporarily closed for refurbishment', etc.

It is a pity to have 2 modules form maintenance of Workflows. We probably will not rebuild Workflow to be dependent on Workflows. Perhaps in Drupal 9.0.

And not only is the functionality potentially redundant, but the entity type created by the workflows module also has an id of "workflow", so I can't imagine good things will happen if both are present.

Theoretically, an experimental module can be removed from core again as is explained in Experimental modules in Drupal 8 (Near the bottom). So as long as it is experimental this module is not redundant.

But considering the similarities (and the same entity names as mentioned in #5), it might.

Just a thought, but what about this module serving as a tool for users to define workflow types to the workflow module in core. To my understanding the core workflows module is for developers and the content moderation module seems to only create workflow type for moderating content with some general predefined settings.

As it is there is no simple way for a site builder to create a workflow type that can be used for any entity or purpose they desire.

That might be a good purpose.
I was planning to merge the workflow submodule and the Workflow UI submodule, but I should then reconsider that.
The workflow consutructors should work with fancy stuff ike 'plugins' and 'thrid party settings'.
We need to dicsuss this with the Workflows people.

This is indeed interesting.
I am using this workflow module for a featured content workflow. I don't think I can do that with core's workflows module

Now there is the workflows_field module for core workflows (http://drupal.org/project/workflows_field).

Is there a current breakdown (pros/cons) of the features in Drupal 9 core Workflows vs. Workflow(contrib)? We are moving from Drupal 7 to 9 and have a custom Workflow with different permissions per state. I wasn't sure if core Workflows will support our needs.

AFAIK, there are 3 key differences between this module and the core Workflows module:

1- Workflow access: Provides a way to control access to content according to their workflow state
2- Fieldable: This module allows attaching fields to Workflows
3- This module attaches workflows as fields on entities. Though as mentioned by SocialNicheGuru, "Now there is the workflows_field module for core workflows (http://drupal.org/project/workflows_field)" I haven't tried that module.

+1 for being enable to add workflow to different entity types, especially if they are custom entity types.

There should really be an explanation of this on the module's project page. On first reading it seems like this must be a legacy module from before Workflows and Content Moderation were part of core.
Even once it becomes apparent this isn't the case, it's not clear what the differences are. Could this module change its name? Workflows and Content Moderation don't appear to be in 'experimental' now. It looks like they're here to stay, which I think makes a strong case for changing the name to something that hints at the functionality being offered.
For what my two cents are worth, I'd like to see this additional functionality in a module that enhances the core module rather than competes with it; especially since the rest is so similar.

Agreed this should be explained on the project page.

As for merging the functionalities with core Workflows, this would be ideal but AFAICT the 2 modules are architecturally very different, so I am not sure if this is feasible... Personally, I prefer the way this one (Workflow) works, having a more generalized workflow per field & entity approach. It allows for greater flexibility and expandability.