In reply to Hamish.

The argument isn't that the core blocks are the end-all-be-all of laying out a web page. This is a post for helping users make decisions on whether they might need a block plugin and theme authors for creating some of these solutions as patterns.

The a11y issue with the columns block was fixed in Gutenberg 10.5 and will ship with WordPress 5.8. As for dynamic posts/content, the first version of the Query block is also shipping in WordPress 5.8. You can install the plugin right now if you need those features.

If you need specific block options based on screen size, yeah, you'll want to grab a plugin for that. For this, at least, we agree:

The most useful blocks do something that WordPress is incapable of doing alone or adding elements that do not exist.