If you cannot conceive of any application where store and retrieve inter-version portability is more important than performance then you have a very limited imagination yourself. Perhaps that's why you hide behind anonymity.
PHP 'serialize' doesn't seem to have a problem with either performance or inter-version portability yet we're stuck the Perl world with a "use at your own risk" core module for what should be a core piece of functionality. Storable could happily live on in CPAN and be an invaluable source for those who need the 'performance' and understand the risk.
When you don't 'own' the system you're code runs on you have to accept that the world around you may change, sometimes without notice. When that happens, you better not be depending on Storable to keep you running. Of course if you live in a bubble you're free to continue making what ever choices you want.