Ubuntu vs Debian for the home server: the family feud, settled by hardware

This is a family argument: Ubuntu is built on Debian, and every choice Ubuntu makes is a choice Debian declined. For a home server, "which is better" is the wrong question; the right one is "which will I still be able to fix at 11 p.m. on the Sunday I actually attempt maintenance."

Where Ubuntu earns its opinionated choices

• Hardware freshness. Newer NICs, Wi-Fi cards and CPU microcode arrive in Ubuntu's HWE kernels without surgery. Debian stable ships what it has tested for age - rock-solid and occasionally too old to drive last year's laptop. Buy a mini-PC with recent silicon: Ubuntu makes the first hour friendly.
• Documentation gravity. Every home-server tutorial on the internet is written against Ubuntu or its derivatives. When you search an error at 11 p.m., the answer is written for this box. That's a real feature; don't let anyone tell you otherwise.
• The managed bits. Landscape, unattended-upgrades configured by default, and a free personal Ubuntu Pro token (home-lab tier - verify the current machine allowance on Canonical's own page) that patches universe packages too.

Where Debian is the better answer

• No Snap tax. Ubuntu's Snap-first habits - notably the loopback interface it creates for Docker's benefit - will bite you the day a DNS container refuses to bind port 53, because systemd-resolved already lives there. Debian's plain apt has none of these surprises; what you install is what is running.
• Stability as personality. Debian stable's release cadence is "when it's ready," and its upgrade path is the smoothest in Linux because everything moves at once, rarely. If your server hosts a family archive and a media shelf, boring is correct.
• Resource humility. A Debian netinst with the few packages you choose genuinely idles smaller, boots on older RAM, and stays that way - no first-boot package flood.

The verdict, as a rule

New hardware, want Docker/Kubernetes/play-it-from-tutorials life: Ubuntu Server LTS, and disable what you don't use the day it annoys you. Old hardware, static services, "install and forget": Debian netinst. If you'd rather learn one system forever than argue, learn Debian proper - Ubuntu is Debian with a personality, and the personality is a subscription to its choices. Whatever you pick: name the machine, snapshot before upgrades (Timeshift or plain LVM state), and test your restore while the thing you're protecting still exists.