I'm lost at the very first line of your example code where it appears you are assigning a hash to a scalar.

I feel your pain!
For a long time, this sort of syntax was alien to me. But it is worth taking time to understand.

$config = {
  verbosity => 3,
  logger    => 12,
};
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This is assigning an anonymous hashref.
Consider this instead:

# Create a hash
my %myhash = ( 'verbosity', 3, 'logger', 12 );

# Assign it to a hashref
my $myhashref = \%myhash;

# To get the same result
# without the hash variable
my $myhashref = {
  verbosity => 3,
  logger    => 12,
};
[download]

For many years, references were beyond me.

It is easy to just say that we don't understand them and dismiss that as the way that it will always be. This is what Carol Dweck describes as a "Closed Mindset". The alternative is to reframe the problem. Instead, say that we don't know how to do it yet but we can learn - it might be difficult, but it is possible. Then the only question is whether one is prepared to put in the effort and be humble enough to ask for help and receive wise counsel from those who provide it without getting defensive when information and methods that don't make sense are presented. Nothing makes sense until it has been learnt...that's why people used to think the Earth was flat...

I asked here in the Monastery about references. Several Monks gave conceptual models that didn't make sense and examples that I didn't understand. I tried to use references in test code and failed. I tried changes, sometimes at random, until I got something working or, at least, giving a different error message. I asked if my understanding of what was happening was right. Slowly I grew to understand...

You too can understand references, OOP and trigonometry...but it requires an open mindset...

I'm lost at the very first line of your example code where it appears you are assigning a hash to a scalar.

Please read perlreftut.

All is global in the computer's RAM!!!!! ;)

A global variable is bad style not because it is just there but because you don't know who uses it. So, trivial example, if you change its name you rely on Perl's strictness to tell you who from those using it still use the old name which is now undefined and you need to fix it.

$config in the line that confused you is only global in the computer RAM and in its limited scope when it was created from a file. ***I CHOOSE WHO SEES/ACCESSES THAT $config*** by passing it's reference (which is an address to the computer RAM which does not need to concern you at all) explicitly to them (subs). That's hugely different than declaring it global and any sub deciding to access it. Many times I revisit my code and can't remember a thing. Worst things happen when others work on your code. So, difficult to keep track where all the globals are used across my code. So, it is not political correctness. @^$^@* political correctness AFAIC. It is a way to deal with complexity. And a good one too.

Anyway, I feel that I may confuse you, so I will not insist on this subject unless you ask.