I think the essential point about attributes is to DRY when marking subs and variables.

so this code might be explicit but repeats the subname hello as a string.

around 'hello' => \&makebold;

Please note that attributes are not necessarily wrapping code.

One use-case for instance could be to set a breakpoint for the debugger

sub tst :break {
  ...
}
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Another to restrict the type to variables

my $y :Int;
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which might be very helpful when trying to translate Perl code to a typed language like C.

All use cases could be achieved by adding tst or $y to a hash somewhere, but the possibility to do it right at the point of interest w/o name repetition can be very handy and avoids headaches when refactoring.

Just imagine the overhead for a refactoring tool to find all hellos after sub hello was renamed.

update

I'm no expert of Moose's compile phases, but a DRY notation of around using attributes would look like

sub hello :around(makebold) {

  return "ohai";

}
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