A pure Free-Software distro is a very hard ambition as well as an hard goal to accomplish, you have to deal with your hardware and if your hardware is not compliance with the free Software it is almost impossible running a pure libre distro. But back to time when even installing a standard distro was an impossible task, Ubuntu came out helping a lot of people making easier installing linux on whatever hardware. However we have to flip the point of observation, at the beginning there were just free drivers mostly made through reverse engineering, most of them were too buggy or unreliables, and the few closed drivers were hard to obtain or unavailable to the end users. Hence running a linux distro and having a laptop or a PC with 100% hardware recognized was very hard to achieve but not for Ubuntu. Ubuntu made easy installing blob binaries on Linux and making your hardware properly working, cool! All of we are in debt with Canonical for this because Ubuntu broken this barrier and helped all the distro to achieve the same, pointing the direction to follow. The main point is Ubuntu used closed software to achieve its goal, it pursued a pragmatic approach instead of an ethical one and it was right.
Ubuntu also decided to focus on a smaller set of packages respect to Debian, from which it derivates, and it takes care only the packages available on the "main" repo while all the others are in the "universe" repo and are handled by the community. However to release Ubuntu the packages in "universe" don't need to be bugs free like the ones in Debian. As a matter of fact Debian is released when all the critical bugs are closed, then basically all the packages in Debian stable are working while, even in a Ubuntu LTS, the packages that are in the universe repo can still be buggy.
An Ubuntu LTS can have software more updated than a Debian Stable but the latter is 100% reliable and secure. Ubuntu takes care only of the packages that are strategic for the Canonical's business and has several partnerships with hardware and softwares vendors to provide binaries blobs and closed software on his platform in the name of the pragmatism and customers satisfaction. Fine, but now is clear that Ubuntu is not the best choice for a pure linux distro, when you take out from Ubuntu the closed softwares you lost all the points that make Ubuntu a pragmatic distro and eventually you have just a distro with an unusual repositories organization and with most of those packages available quite buggy.
Even FSF noticed that and as a matter of fact they switched from Ubuntu to Debian for their gNewSense distro. It is important to remember that Debian was financed, long time ago, by the FSF itself because it actually promotes free software by default but it is not restrictive like the FSF does and that caused a separation that still continues.
My suggestion is, if you like to have a FSF endorsed distro based on deb you had better to avoid any Ubuntu derivates and move on the ones based on Debian like the already mentioned gNewSense or PureOS and don't forget that Debian is 100% free software by default.http://gnewsense.org/https://www.pureos.net/https://www.debian.org/
gNewSense is a fully free software GNU/Linux distribution.Free software is software that respects your freedom. You can use it without restrictive licenses, make copies for your friends, school or business. To use free software is to make a political and ethical choice asserting your rights to learn and to share what you learn with others. It is bu...gnewsense.org