> What does Steam look like 60 years from now?

Does it matter? You are treating this like these games are some valuable collector's items, when they really are just toys you play once and then never touch again for the most part.

But let's assume you had physical copies of all of these games you own on Steam. Once you are gone, there is a > 90% chance that whoever inherits it, will throw it away, just like Millenials now are throwing away all this junk they are inheriting that Boomers used to collect.

The point is, Steam is good enough for all practical purposes, which is to acquire and play games in the now.

My library includes games I played with my father and games I played with my own children. Given the option my children would certainly revisit their favourite titles with their own children one day, or for their own nostalgic memories.

One thing you are missing with your logic is that "throw it out" is probably more like "give to charity", the unwanted goods are not necessarily being destroyed and may be redistributed to people who do value them. If my kids didn't want my Steam account I'm sure there's others who would, and preservation groups and museums that would probably take it.