Historically, Debian didn't ship proprietary wireless firmware in the installer (because it was proprietary software, and Debian doesn't do proprietary), so you couldn't install it on most laptops without plugging them into wired Ethernet to download the wireless firmware packages from non-free.

They changed that a few years ago, but plausibly the underlying prioritization of end-user experience is still lower than Ubuntu's degree of user focus.

I still wish Mark would rename his company "Ubuntu". He's a great guy, the company does great work, but I keep getting undeserved credit for it because we wouldn't sell him the domain name.