The main disadvantages of LaTeX macros (already defined commands, journals requeriments,...) has been well covered by the comments, so I will focus on the opposite aspects:
I particularly hate unsolicited autocompletion (like in Word or LibreOffice) because often is not helping, but distracting. A requested autocompletion, either through a shortcut (
ctrl-B) or a menu (
LaTeX> Font Styles> Boldface) is fine, especially if the user can define the shortcuts. But a little problem is to remember all the shortcuts and menus. If you change between several editors for some reason, this could be a problem.
Instead, LaTeX macros do not depend on the editor. The code is not obscured even for others, if macros are well commented and formatted in the preamble (and used judiciously). At least no more obscured that code in packages or classes, that sometimes is not well documented. Instead, this could make the content even more readable since text is cleared of many LaTeX commands. In fact, separation of content and style is a major objective of LaTeX. Isn’t it?
But above all, you always can change very easily what your macro has done in the last compilation, but may be not so easily what the autocompletion has wrote. In the end, LaTeX is nothing more that a set of TeX macros, that is, the use and abuse of this wonderful advantage.