You may have to group elements, yes. But generally speaking, they already are grouped in some logical sense. And you can do a lot now with grid, without having to wrap child elements in containers. It's not absolutely separated but to great degree it is (in my experience at the very least).
And yes, you can select previous elements with :has(). Here is an article about it: https://tobiasahlin.com/blog/previous-sibling-css-has/