What happens when you insert a row at the beginning or end? That's a bit less "certain", for most people, and can lead to incorrect sums.
Re the grandparent, Excel does have named ranges. Some it constructs on its own based upon column headers and whatnot. Others can be explicitly defined.
Unfortunately (again), the tools/widget Excel provided -- back a decade or more ago, when I lasted used it intensively -- were "out of the way" and fairly limited in terms of their interface and behavior/functionality.
Still, if you have e.g. a column headed REVENUE and a column headed COST, you can insert "= REVENUE - COST" into an adjacent column in the same row, and Excel will know what you mean. And... in this case, it is less likely to become "confused" (do what it's programmed to, versus "do what I mean" -- DWIM) if/when you move individual cells around.
P.S. What I do wish, or did, was that Microsoft would better document and explain publicly some of Excel's underlying behavior and edge cases. It can take some time, exposure, and mental effort to trick some of these out.
Excel is a powerful tool that does its job very well. A good part of the problem is that with its ubiquitous distribution and use, much of the time this is like handing a toddler a loaded handgun to play with.
The handgun is functioning just fine. Its deployment and use in this case is, however, less than optimal.