Let's keep it simple:
A user dashboard for my clients where they can see website visitors (GA), Form entries, latest blog posts, recent changes...
A FULL Rich Text Editor that allows editors to make more detailed texts (something like TinyMCE)
User roles to allow specific users to for example edit their own blog posts/pages/...
SSL Certificates (yup, again)
Blog-related elements like share-buttons, comment sections, page stats (like amount of shares/visits...)
Dynamic Sliders, Lightboxes, Tabs...
Multi-language feature (possibility to add translations)
Deeper integrations with Mailchimp, Zapier, CRM's and other mailing services
Folder structures with more file formats supported (images, videos, pdf,...)
A search function (this would allow for bigger websites like directories, even small 'web apps')
Looking forward to see you work on these features.
Thank you so much by the way, Webflow.
You have already made me more money than Wordpress has ever been able to. Yay!