Depends on personal usage and preference. I don't want to have to setup Windows and all my programs again if something crashes C: drive, so I image my disk every month before the MS 2nd-Tuesday Update.
The image, with verification afterwards, takes ~30 minutes for the 170-180 GB usually in my C: drive—unlike you, I have a lot of software, much with custom settings. If I had more on C: drive, say another 500GB of games, the image would be ~2 hours—which would be a bigger disincentive to not bother, since it wouldn't handily fit in with a short absence for say dinner.
The image would also of course be 4 times bigger—so ~400-450GB—and therefore far less attractive to store on another physical disk, which may already have quite a lot of data on it, including of course large normal file backups of working data.
A small C: partition also makes cloning the drive easier, so you can always have a spare C: sitting there ready to pop in if anything happens the working one. This is especially useful when building a PC, or during a major OS upgrade.
So it's not pointless, but of course not necessary either. Like all security practices, it's all related to what the pain of loss would be.
Not for me, and especially not all the software customized settings—that would take a lot longer to replicate than reinstalling Windows.
But for a PC used only for gaming, then yes I agree. Windows and games can be easily reinstalled if one has decent internet speed.
@Jayden Millan All above isn't relevant for your question—the answer remains that you should default to having your current game(s) on your fast drive