I’m completely guessing the following but it’s an interresting topic so I’ll try:
Here’s the list of in-development features.
In progress | Webflow Wishlist (multilanguage is missing from the list)
If form attachment already requires Business hosting, then all of them could. Multilanguage, Ecommerce, I always thought they’d be for the Business plan only. It makes sense as they’re heavy features from development to production.
However, Grids, Pagination and Conditional visibility are direct features of the Designer, and they impact sites that can be transferred etc, so they logically should be delivered for all hostings.
In the end, some features are requiring more server power, some don’t. Attachements, multilanguage, ecommerce do. Grids, pagination don’t. Conditional visibility, I guess, is only like another way to filter, so it uses power but not more than another filter (and less that many more filters used to try to mimick the feature)