This should be a proper thread, I considered that it's moved into one.

> I have no problem using or understanding that noisier indirection syntax, but there must be an explanation beyond my current understanding of the arrow operator. Thoughts please?

Short answer

Symmetry!

$arr_ref->[@slice] doesn't "work" because the analog $arr[@slice] also doesn't do what you mean.

NB: @arr[@slice] is different.

Long answer

Perl is pretty consistent that $ means scalar and @ means a list. The whole context rules depend on it. Something like $ref->[@slice] is as misleading as $arr[@slice] because a scalar has to be returned. (What's happening here is that the scalar value of @slice is calculated instead of a list)

For a slice the correct syntax is @arr[@slice]

Compare the analogy

  DB<12> @a = "a".."z"; $ar = \@a

  DB<13> p $ar->[1], $a[1]
bb
  DB<14> @slice = 1..3

  DB<15> p $ar->[@slice], $a[@slice]
dd
  DB<16> p $ar->@[@slice], @a[@slice]
bcdbcd
  DB<17> p @$ar[@slice], @a[@slice]
bcdbcd
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The deref syntax in line 16 is newer and was introduced to avoid @{...} constructs like in line 17 (In this case the brackets are optional)

What you are suggesting would break the symmetry and cause confusion and bugs.

Updates

Added short answer