It's more than thousands, and not only it's not reasonable, it's not possible.
Plenty of games run on some critical optimizations that exploit native code quirks that may or may not hold up only because Windows papers over them by special-casing the game process at OS level. The source of such games may be stuck in IP limbo, with five different studios/companies claiming ownership (three of them dead or bankrupt), and even then, the only person who knows what and how needs to be reimplemented is on a remote tropical island, working for a competitor / happily retired / stuck collecting trash for a living, depending on how their career went.
Takes only a few such cases to turn out to be some well-known games with substantial legacy fanbase hoping to relive some childhood memories, to risk seriously damaging the "supporting everything" marketing angle.
Emulating underlying runtime is safer and more practical choice.
Plenty of games run on some critical optimizations that exploit native code quirks that may or may not hold up only because Windows papers over them by special-casing the game process at OS level. The source of such games may be stuck in IP limbo, with five different studios/companies claiming ownership (three of them dead or bankrupt), and even then, the only person who knows what and how needs to be reimplemented is on a remote tropical island, working for a competitor / happily retired / stuck collecting trash for a living, depending on how their career went.
Takes only a few such cases to turn out to be some well-known games with substantial legacy fanbase hoping to relive some childhood memories, to risk seriously damaging the "supporting everything" marketing angle.
Emulating underlying runtime is safer and more practical choice.