Hmm ... not sure where to ask this, so please remove or replace this thought experiment if it doesn't belong on this channel.
Kevin talks alot about fixing/doing up mobile layout first and then going on to desktop layout. With the advent of auto-fit/fill and minmax usage in grid, does this always has to be the case? With basic designs like the CRL Flexbox challenge 4, all sections could be placed in a main grid, and all the content within each section could be nested grids, all with an auto-fit/fill and minmax. That would automatically make it responsive and stack the content as normal in mobile layout.