Man of Honour
And yet I have two 1 terabyte drives completely filled with maybe 30 games. Mysterious
You're killing your own argument by assuming that having a lot of shovelware and ancient games means having few to no large install games
No. I'm understanding what an average is. I'm understanding what a possibility is. I'm not assuming that a collection of 25,000 games from Steam will absolutely definitely fit in 100TB, that it's impossible for it not to happen.
You're assuming (and I neither know nor care why) that it's impossible for a collection of 25,000 games from Steam to contain a very high proportion of games with a (by modern standards) small or very small install size. Your own collection of games is irrelevant to a collection of 25,000 games. As I said before:
Few if any people with a normal modern game library would have an average game size of 4GB or less. But we're not talking about anyone with a normal modern game library. We're talking about people with 25,000 games from Steam. That would have to include many pieces of asset flip dross, many small indie games and many older games. Many of those would be far under 4GB, which would significantly reduce the average game size.
For example, the first game in my Steam library when sorted alphabetically is Avadon: The Black Fortress. Space taken on disc is 114.73 MB. Some games that size and a 50GB game would average 4GB per game.
I'm fairly sure it would be possible to select 25,000 games from Steam that had an average installation size of 4GB.