So, some things, otherwise tedious, could be auto-implemented. For example, equals() a hash or equals() an object are equivalent but the hash can be cleaner and simpler.

Ah, I see what you mean. Well, I do think that some of the classic issues of comparing data structures still come up. For example, are these two hashes the same?

my $x = { foo => { bar => "quz" } };
my $y = { foo => { bar => "quz" } };
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The answer might appear obvious, but note that $x->{foo} ne $y->{foo}! So I think it's still up to the implementor to decide how to determine whether their objects are the same. For simple recursive data structure comparisons, there's e.g. Data::Compare.