First sale doctrine applies to some software and not to others(often having to do with possessing physical media). Their general argument that it doesn’t is when they say it’s a “license” but that license gets superseded by the first sale doctrine where applicable. It’s a general shit show.
Edit: an example of the shit show nature of this: “Can you modify a copyrighted work you were sold and then resell it without the copyright owner’s permission?” The courts are split on this with one saying yes and another saying no. And mind you that’s just pasting pictures onto things with no EULA involved. What happens if you modify a physical representation of software and resell it? If Nintendo or John Deer decided to place restrictions on the resale of consoles, forcing them to be above a certain value or in violation of their copyright license re the software inside the console/tractor, would that violate the first sale doctrine? Who knows.
EU is similarly confused about first sale doctrine as the US is. Steam was ordered to allow games reselling by a French court but eventually got it reversed on appeal, for example. https://www.bfmtv.com/amp/tech/gaming/la-justice-se-prononce-contre-le-droit-de-revendre-ses-jeux-video-dematerialises_AN-202210240308.html
This is despite the first sale doctrine being established as part of digital media in the EU with https://curia.europa.eu/juris/document/document.jsf;jsessionid=A87D18058F3F93DB5719943E51D3B25F?text=&docid=121981&pageIndex=0&doclang=en&mode=lst&dir=&occ=first&part=1&cid=6657274