I actually think grid is simpler. The flex properties are confusing and make common cases complicated. Grid fits my mental model of what I am trying to achieve pretty much 1:1.
Grid doesn’t really use a new type of element either.
I’m just happy to be able to layout things 2D in a way that isn’t totally bonkers and do weird contrived calculations to make everything fit in the viewport. My only wish remaining is a unit that is like fr for grid layout but can be the same value for both row and grid (so an equivalent to vmin for viewport)
I think Grid is a bit more complicated, more to learn. CSS is getting better but at the same time it's getting more complex in total.