How exactly do we know that?
How much potential sales do they lost?
For Console+PC owner, does that affect their decision to just pirate it?
Would the PC sales cover their Porting cost?
Here's a simple solution deferred the all PC port games until new version of Denuvo or stop porting it all together.
Piracy is disgusting no matter how you tried to defend it to be.
No one is defending anything.
I don't know about "most" not being lost sales but there are people who will pirate things and not contemplate buying them at all, you can't lose sales if they weren't going to buy it in the first place.
People also seem to be forgetting that piracy will thrive wherever it is possible, Consoles or PC it doesn't matter, there are modern consoles which you can play pirated games on, and the last generation consoles had a strong piracy scene.
Refusing to release PC versions of games because of an unknown quantity of people who will obtain ilegitimate versions is ridiculously silly, this is how you will lose sales, by not supporting the platform and profiting from the people who will buy the game.
There have been many titles which don't have Denuvo or are pirate-able and have become great successes on the platform, many of these titles have sold over a million copies.
Such as: The Witcher 3, Dark Souls 3, Grand Theft Auto V, Civilization VI, Fallout 4 and many others such as Borderlands 2 and Skyrim, these two games have been out for a couple of years but both games have sold over 6 million copies and have very active playerbases.
Just look at how successful Playerunknown's Battlegrounds is, it launched March 23rd this year and has sold over 2.9 million copies (going by Steamspy) in around 2 months and 14 days. That's almost the numbers Horizon Zero Dawn has done, which has allegedly sold around 3.4 million copies in around 3 months and 4 days. Of-course, there are differences in their pricing etc but it shows how successful PC Games can and have been.
Being concerned about people who have no intentions to purchase games and not releasing a PC version because of this is the worst thing any developer/publisher could do, there are millions of PC Gamers who buy games and support the developers, the PC platform makes money, this is why so many games have come, and are coming to PC such as Destiny 2.