Exploration. Related #25501 #25502.

These types of blocks are a very common request that we have stayed out of tackling in core for multiple reasons — primarily the reliance on JavaScript on the front-end for most implementations. The reality now, however, is that the CSS spec has added great new native tools with good browser support to try to accomplish some of these displays without relying on JS, employing properties like scroll-snap-type and scroll-snap-align.

Combined with inner blocks and layout container, including viewport units, it could easily accommodate full screen display options:

It might be a good time to explore how we might build a container or add these container behaviours to flex groups. Would be good to work as a generic container that could be leveraged for galleries, custom inner blocks, post lists templates, etc.