He's a 7-footer
The NBA has witnessed an evolution in recent years, moving from the small ball era popularized by the Warriors dynasty towards the need for a dominant offensive big man. The last two NBA Champions featured 7-footers who could stretch the floor and be a force on the offensive end of the court like Nikola Jokic and Kristaps Porzingis.
Markkanen can be viewed as a Porzingis lite at this point in his career, a stretch 5 who has an offensive skillset with some rim-protecting skills that can be refined. He's also European, like the aforementioned big men, so maybe there is something to having a European 7-footer in the NBA.