Actually you can share state in the package variables, but only one set of them.

This pattern is similar to a singleton object in OOP.

(The modular interface of Data::Dumper is a good example for that, with the global config vars, like $Data::Dumper::Indent )

But you are right, a very good reason to use methods instead of functions is if they all start to look like this

package Do_Something

my %repeated = init();

foo( X, %repeated);

bar( Y, %repeated);

...
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then it's obviously better to write

my $obj = Do_Something->new(%init);

$obj->foo(X);

$obj->bar(Y);
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especially if there is a chance that you might need to have different initializations in the same code

my $obj2 = Do_Something->new(%other_init);
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( see Data::Dumper again with it's alternative OOP interface, where the configs are encapsulated in the objects like $OBJ->Indent([NEWVAL]) or $OBJ2->Indent([NEWVAL]) )

On a side note: I prefer to think about objects like actors which do things, not containers which have attributes.

So reducing them to shared data is not the whole picture.

Last but not least: PBP lists some criteria when to use what...