What is the most client friendly CMS for Hugo sites? I have seen Forestry and it is OK. Coming from Craft CMS, these UIs do not seem that great. Any suggestions?
Netlify
Netlify CMS looks great also. Just curious what makes it better than Forestry?
I quite like the editorial workflow of Netlify CMS:
publish_modeoption allows you to enable “Editorial Workflow” mode for more control over the content publishing phases. All unpublished entries will be arranged in a board according to their status, and they can be further reviewed and edited before going live.
As always: It depends. I’m more used to Netlify because they have a great free plan. Don’t know enough about Forestry to really being able to compare.
Netlify CMS is open source. Forestry is not. That’s the big one.
With Netlify you have to configure each and every front-matter field through a config.yml file. Forestry is able to mostly auto-detect your fields, so it’s more plug-n-play.
Neither of them offer good (any?) multilanguage support for your content.
I love Netlify, but I just can’t get warm with their CMS on Hugo. I can’t get my “old” blog running on it (14 years of posts, 4000 posts). It’s not really usable with Hugo’s (not so) new feature of page bundles. Or I did just not found the perfect tutorial of how to use it 
I think it’s good for low-frequency sites with not so many posts though.
Does the term CMS even apply to Static Sites?
I know people use this term because its popular, but when you compare the feature list typically associated with Content Management Systems, it seems like many would be missing by default.
It does, because you Manage the Content 
Collaborative: multiple users can change the content (on Netlify CMS via personas)
History Editing: via GIT repository
Web Based: check
Separation of content and presentation: Check (content folder, theme folder)
You think about database based CMSses and that’s not Hugo, right, but CMS - resounding yes.
This discussion goes on in another topic: