Not feasible.

There is no way to identify a non-Steam game but by its executable.

This would require a server side stored number in a database per game per player. It's cloud data that would have to be synchronized over several sharded regional databases which costs both storage and transfer.
For you yourself it's not much, but if you expand the scope to 40M globally daily active users, it grows exponentially, especially so because you can't use the executable as a guaranteed and unambiguous identifier on the game side that can be deduplicated to reduce complexity.

If you want this sort of statistics, get the game on Steam instead.

Originally posted by Trico:

I’d like to suggest a feature enhancement for the non-Steam programs that users can add to their Steam library. While it’s currently possible to launch non-Steam applications through Steam, the platform does not track how long these programs are used.

It would be very helpful if Steam could also record and display usage time for non-Steam programs. Many users, including myself, use Steam to conveniently access various types of software—not just games—and having a unified place to monitor usage time would be greatly appreciated.

Use something like Playnite to track and provide statistics.

Originally posted by Ettanin:

Not feasible.

There is no way to identify a non-Steam game but by its executable.

This would require a server side stored number in a database per game per player. It's cloud data that would have to be synchronized over several sharded regional databases which costs both storage and transfer.
For you yourself it's not much, but if you expand the scope to 40M globally daily active users, it grows exponentially, especially so because you can't use the executable as a guaranteed and unambiguous identifier on the game side that can be deduplicated to reduce complexity.

If you want this sort of statistics, get the game on Steam instead.

No need for anything server-side. Just a text file of executable names and times stored on the player's machine with optional backup via the cloud-save mechanism. I don't see such a file growing beyond a few kilobytes in any realistic scenario. The filename probably wouldn't be more than 50 bytes, and the time in seconds would be under ten, so call it 60 bytes per program. That'd be 6KB for 100 programs, which most users probably wouldn't be doing.

Even if every user had 100 programs tracked, then across 40M users, that'd only be 240GB in total. Valve probably uses that much for the saved games of a double-digit number of Factorio players, so it'd be negligible in the grand scheme of things.

and what monetary profit per game would Steam gain from such feature? There is no incentive for Valve if you can simply buy the game elsewhere then import it into Steam to make use of Steam's library features beyond the bare minimum.

its been asked for about 10 years, maybe more and never once updated. non steam games wont get many community/steam features added.

Originally posted by Trico:

I’d like to suggest a feature enhancement for the non-Steam programs that users can add to their Steam library. While it’s currently possible to launch non-Steam applications through Steam, the platform does not track how long these programs are used.

It would be very helpful if Steam could also record and display usage time for non-Steam programs. Many users, including myself, use Steam to conveniently access various types of software—not just games—and having a unified place to monitor usage time would be greatly appreciated.

The incentive for getting a game on Steam is the Steam features it provides.