Thank you Gadzhi. That makes sense, even though I am still finding it hard to nail down some solid rules of thumb. After doing some more in-depth research, I am now finding out that actually what I am referring to as the "Grid system" is still in development, so I guess the columns and containers that I was referring to are just the currently most commonly used layout method, based on concepts such as the 'display' property and the box model.
What I am also learning is that these tools are not really intended for layout purposes, and therefore the Grid system is now being developed by the W3C. That was not so obvious to me when I posted my question. According to what I am reading, the combination of grid+flexbox (and not flexbox alone) is going to allow for a lot more flexibility in web design. So my guess is that the same way that you guys have incorporated Flexbox into webflow, we'll see something similar for the Grid system, once it starts to get supported by most browsers? I have just posted this as a request on the Wishlist site, I was actually a bit surprised that it was not there already, since this looks like a very desirable feature to me! https://wishlist.webflow.com/ideas/WEBFLOW-I-480
Back to my question, I haven't found any in-depth resource that explains how to combine together the existing layout methods (columns and rows/Flexbox). For example, this is a tutorial called “Grid by example”, it’s pretty good but it applies to the yet-to-come Grid system, and says nothing about the existing replacements for it, nor is Flexbox mentioned in any way. It would be great to see something similar, that applies to the layout tools available in Webflow:
I would love to keep this short but the reality is, I am struggling to find some clear, definitive information out there. I’ve found several articles saying that Flexbox is not intended for high-level page layout, but some of the Webflow tutorials show how to use it for things like sidebars, or a footer that always appears at the bottom of the page, even when the page content is limited. My understanding is that this is because we don’t have a truly semantic Grid system yet, and with the current method, Flexbox is the best way to achieve certain results. It’s just my guess, though. And the overall question: as far as it looks good, why can’t I just use Flexbox for page layout? Are pages going to render more slowly if we do so? What are the situations in which it’s still advisable to stick to the row/columns method?