Earlier quoted context omitted.
Regular expressions and glob(7) expressions look superficially similar, but it is mostly an illusion; they both use * and ? as common metacharacters, but both of those characters mean different things in the two systems. Only the [ and ] characters are used more similarly, but even those have their differences. The two syntaxes only have one common function which functions identically in the two systems, but it is in…
To be pedantic: You're conflating the syntax of regular exprssions, with the (computer science) concept. Glob patterns are a kind of very resticted regular pexressions. Ksh extended the glob syntax so it has the full power of regular expressions in the computer science sense - though without all the extensions of modern regular expressions.
“Globs do not include syntax for the Kleene star which allows multiple repetitions of the preceding part of the expression; thus they are not considered regular expressions, which can describe the full set of regular languages over any given finite alphabet.”
— https://en.wikipedia.org/w/index.php?title=Glob_(programming...>