For me, by its ubiquity. It has desktop and servers images [1], cloud images for containers and virtual machines [2], and base images for all kinds of embedded devices [3], all with multiple architectures (amd64, armhf). I run it on everything from servers and desktops to QEMU ARM guests and e-readers.
[1] https://releases.ubuntu.com/20.04.1/ [2] https://cloud-images.ubuntu.com/focal/current/ [3] http://cdimage.ubuntu.com/ubuntu-base/releases/20.04.1/relea...
That's what I need. Predictable LTS release every two years is good.
I forgot that was even a thing. I don't think any other Linux vendor did anything who made it that easy to just use their OS.
1. Using the most popular distro is an advantage
2. Polish. The little details add up over time. I tried switching to Mint and had various small problems that I didn't have on stock Ubuntu.
When I first heard of Ubuntu, it was said to be quite a bit friendlier to install, so I tried, and pleasantly found the reputation to be true. It felt like someone had endeavored greatly to make my life simpler, including the installation process, the bundled software, and the default look of the DE in general (why I thought so, I couldn't remember). It showed a comically colored progress bar instead of screens of text that scrolled too fast to read. They even made it easy to dual-boot with Windows, without making you go through a whole bunch of partitioning stuff. I thought it was amazing.
Nowadays, I find most mainstream distributions to be friendly enough. Debian, Fedora, CentOS, OpenSUSE, Mint, etc. are all pretty refined. The installers have different interface, but, if you just want to stick to the recommended preferences, it's usually straightforward.
So how does Ubuntu differentiate itself, in 2020?
In terms of the packaging, it's a bit mid of the road, not as stable as Debian/CentOS, not as latest as Fedora, and certainly nowhere near bleeding edge. In terms of DE, Unity is gone. Is it just Snap-enabled be default?