Not always—there are definitely practical things you can achieve with Grid that you can’t with previous layout options, I’ve made a couple myself—but almost always.
Most layout scenarios that are in two dimensions can actually be solved with nested single-dimensional layout. Sometimes it’ll be easier to solve them with a proper two-dimensional layout, and I tend to prefer the markup that Grid lets me have, but I find two-dimensional layout that can’t be solved with nested single-dimensional layout to be uncommon.
Also, most interface problems are actually single-dimensional.
I think Grid will become more popular than it is, but never overtake Flexbox as most people’s go-to for layout, because Flexbox is normally enough, and Grid is too complex. I use it from time to time, and I have taken the trouble to know exactly what it’s capable of, so that I know when I should reach for it rather than Flexbox or something else or giving up, but I normally need to look up various properties when I go to use it. Meanwhile, most of what people want to achieve with Flexbox is just `display: flex;` plus `flex-direction`, `flex`, `align-items` and `justify-content`, and there are few enough knobs that you can essentially brute-force it without trouble—and the Flexbox Inspector makes it even easier, in a way that the Grid Inspector can’t really because Grid is just too powerful.
Two big things in grid come to mind that make me use it much more than flexbox: grid-template-areas, and being able to overlap cells using lines.
In general, having a flexible first-class 2d layout is much easier to work with and change later than having nested 1d layouts.