The thing is as DRM has been reduced the market as grown. Perhaps there's a correlation, perhaps not.But having been involved with PC gamers for decades my anecdotal belief is there is a correlation.
You seem to be aware that correlation = causation.
The market has grown because gaming on PC has become a better experience all around, with services like Steam streamlining the process and helping to make PC the most cost effective way to play.
They better spend those 100k in games additional features.
Wanna fight piracy? Make sure your game is good, simple as that.
Only bad games get pirated?
Having a good game might financially insulate you a bit from the effects of piracy. But it's not an anti-theft.