Whether I use an indexed variable vs. an atomic one depends upon the problem I am trying to solve and how I wish to solve it. For example, if I have wish to write or refer to elements in a sequence, list or vector, being able to use indexed variables is quite valuable in readability and worksheet real estate. E.g. seq(a[n]*x^n, n=0..3). Such choices are made when I am writing code, which I perform nearly always within a Code Edit Region.
However, if I am writing mathematical equations that I want non-Maple users to be able to read, particularly if including a subscript is informative, then I use an “atomic variable”. For writing mathematical equations and functions I use 2D-input because it makes the equations more readable and reduces the content on a page. The output of a 2D-input is repetative.
I agree with Carl Love, the atomic variable leads to fewer problems, particularly with new users, which, clearly, you are not. Many of the students in my courses prefer the image of the subscript provided within 2D input, such as F__x or F__Earth. However, when constructing such variables, too often they end up with the equivalent of F[x], only to discover that should they assign a value to x, their worksheet starts producing unexpected outcomes. Thus, I encourage them to avoid subscripts until they are more familiar with Maple.
There is a post on the evaluation of subscripts in Maple by Robert Lopez that might be of interest to readers: https://www.mapleprimes.com/maplesoftblog/208838-The-Saga-Of-The-Subscript
Personally, I enjoy atomic variables. They truly do make Maple input more readable, i.e., more aligned with what one sees in papers and textbooks.