I am undecided but currently use flexbox.

https://hackernoon.com/the-ultimate-css-battle-grid-vs-flexbox-d40da0449faf

https://css-tricks.com/css-grid-replace-flexbox/

https://tutorialzine.com/2017/03/css-grid-vs-flexbox (features a great line “There is no reason to use only CSS grids or only flexbox. Learn both and use them together.”)