CSS Grid is for layout, not tabular data. It allows you to move the presentation of your elements around at different breakpoints regardless of your markup structure.
In general I recommend understanding a feature before you spout off nonsense about it.
I disagree. Conceptually, it is exactly how you would do layout in the old days. This still works, btw, it's just considered bad practice.
It's a bit like saying that a kitchen knife is totally unlike a dagger and completely unrelated in every way, because the former is for slicing food and the latter for stabbing.
Horses were never really "vehicles." We just misappropriated them that way, because they just happen to be big and move around and we can sit on them. Cars are purpose-made to be vehicles for humans.
If a designer shows you their wireframes with their grid lines drawn on top of it, I don't think many people would think "ah! so it's like in a science paper when they're printing the raw data from their experimental results in tabular form."
The fact that some web developers consider them alike is a historical accident.
Cool, but things like this have a marginal positive effect for developers, at the cost of having to learn yet another thing, and making it harder and harder to make a reasonable webpage.