What is a piece of lost media that just no longer exist?

London After Midnight's full cut and that lost Spider-Man movie that only the director has but never released it

(Sorry, I tend to get carried away with these kinds of posts. My bad!)

If there is evidence to suggest that stuff still exists then I don't think it counts as no longer existing. I would assume that something that existed say like in the 40's and then it had only one copy ever to be known of the media but evidence shows in a newspaper of a picture of the media back in the week of the media being released and then news breaks that a fire destroyed the media or something tragic happened like someone accidentally erased the media happens decades later and it will never resurface because it's actually physically gone.

Lincon's lost speech, the only person who tried to write it down (that being William Herndon) gave up after 15 minutes of the 90 minute speech and threw away his papers, meaning that even if the pages he wrote were discovered, which is incredibly unlikely, the rest of the speech is definetly lost forever

True, if not depressing. 

Homemade video games that were never seen outside of some kid's room. Particularly ones from the 1980s-early 2000s, in which floppy disks & CDs were common, but the internet was still rather young. Same sorta deal with homemade movies of that era unless they, or some family member, sells it at a flea market or sends it to be sold in a thrift store & ends up in the hands of someone who uploads random stuff.

EDIT: Remember, those kind of people are far less likely to have much of the money to preserve media of theirs & some may not even have the space to preserve them, with their house being full as it is. That stuff can just be trashed out at any moment, be taken to a dumpster & be destroyed on the way. I learned about Hurrican Katrina at school & it was a horrific tragedy that happened in 2005 that affected Louisiana HARD; the effects are proven to still persuade even today. Just imagine how much homemade media became non-existent because of Hurrican Katrina & other such disasters.

As much as lost media from companies can be unfortunate, it is always a fair bit sadder if a homemade piece of media that whoever made it was so proud of, is now just gone & no other copies of it exist because of the above circumstances. They could've spent 4-5 years on it, but as soon as disaster strikes, it'll likely be gone because it was made at their house on a super low budget, maybe even no budget at all, so they likely didn't have the money to keep it safe.

This is why the internet is so awesome since it lets you upload material that very few people will ever see otherwise, but even then, it's not perfect & LOTS of internet media, even stuff from big corporations, has been lost to time, but the guys at home tend to suffer the most.

For me, when it comes to who suffers from their media becoming lost, my answer will always be the folks at home. Companies may suffer a lot, but that pales in comparison to those at home, the ones who don't have much money to spend on preserving their homemade stuff, instead having to spend it on things that'll allow themselves to live longer, such as food & water.

Some TVTropes user said it best on an old, 2018 version of the real life subpage of Unperson:
"Prior to modern record-keeping (like birth certificates and newspapers) and widespread use of grave markers, billions of people(one count had the number of people who ever lived at 107 billion) are simply lost to history. It isn't a sinister plot to strike these people from history, but simple truth: People who were not well-known and lived fairly anonymous lives, everyone connected to them is dead, stories of an individual lost through the generations, and absolutely no printed records exist of that person's life — either never created or long since lost — no headstone was created of that person and his/her remains have long since decayed into the earth are examples of this "unperson" trope. There is no evidence available that those particular people ever lived."
And even today, you can find a similar heartwrenching quote on the main Unperson page:
"This effect isn't always someone's deliberate decision. History is largely reconstructed from the records of the time, and will have gaps of information when those records do not exist or get destroyed — e.g. in ancient times, when very few people wrote, and most documents are now lost (paper, papyrus and similar materials do not last forever). Another typical example is the people that were largely ignored during their lifetime and did nothing that gave them a place in history, as the records about an average Joe are fewer and harder to locate than those of public figures."