But they won’t need to delete anything. Imagine the storage and data science in 500 years. Probably the whole internet of 2021 will fit into a 2521 usb stick
My 600 GB of Photos begs to differ (I've worn out camera shutters!), you can't find anything without a long search. If you can't find it, you don't own it... so yes, in theory it's there, but nobody will access it, ever... so does it really exist any more?
It's back to the same meta that everyone else says... you have to make something that people want to have around in 500 years as a first step, or you're just pushing against very poor odds.