There's a simple reason why it's not a thing:
Valve wants you to download on demand and not to hoard. Bandwidth costs money.

Since covid, the CCU and, by extent, consumed bandwidth, has risen sharply to the point that massive downloading became unsustainable. That's also why Valve has changed to do downloads only when you truly need them instead of downloading when it was right on available, depending on your recent activity, scheduling games you rarely play for later.

By only making it convenient to install and update games you actively play, Valve saved on resources and didn't need to further expand its CDNs.

Any further form of automation would mean that people begin to hoard downloads again.

引用自 Ettanin：

There's a simple reason why it's not a thing:
Valve wants you to download on demand and not to hoard. Bandwidth costs money.

Since covid, the CCU and, by extent, consumed bandwidth, has risen sharply to the point that massive downloading became unsustainable. That's also why Valve has changed to do downloads only when you truly need them instead of downloading when it was right on available, depending on your recent activity, scheduling games you rarely play for later.

By only making it convenient to install and update games you actively play, Valve saved on resources and didn't need to further expand its CDNs.

Any further form of automation would mean that people begin to hoard downloads again.

I see, thank you for the information and taking the time to explain this! I really appreciate it.