I’m also curious about how game value depreciates.

Games tend to go on sale to sell more copies later in their lifespan, attracting customers that weren’t going to pay the original price for it.

It sounds like you’re saying that the game can’t be played for as long if you buy it later, which doesn’t really make sense to me.

I might be a biased, as I’m one of those people with a few thousand hours into Factorio, and several hundred into other factory games.