Not sure if this has been discussed somewhere else. If that's the case, please point me there.

In the Columns block, there's a toggle that allows you to choose whether columns stack on mobile or not:

In the Query Loop block, when we select Grid View for posts, they always show up stacked on mobile because this option doesn't exist. That prevents us from achieving designs like the one below on mobile.

Mockup	Gutenberg

I propose we add it to allow more flexibility to create layouts.