Arkane Studios is still picking itself up after being blown into a million pieces at the launch of Dishonored 2 on the PC, which has horrible optimization and massive performance issues. The developer is distressed over the PC performance issues, but it looks like you'll still need a beefy PC to play Dishonored 2, no matter what.
You might remember that you need a GeForce GTX 1070 to run Dishonored 2 on Very Low at 1080p, barely hitting 40-60FPS. Dishonored 2 Game Director Harvey Smith tweeted at the time: "That rig on very low and 1080 should run around 60fps", when asked about a GTX 1070 level PC.
But in a recent tweet, Smith said: "game will always need a beefy pc for ultra, but there are a number of fixes we're making". So there you have it. You'll always need a monster PC to handle the game, proving that it's an unoptimized mess - because if it wasn't, then the graphics need to justify the huge GPU requirement to handle Very Low at 1080p.