The advantage here is that they sell phones.
It is very difficult to install Lineage OS, as it is completely unclear which phone one should buy to install it. There isn't a single viable answer online for the question:
"Which phone should I buy for Lineage OS".
I am dead serious!
The support is up to individuals able to produce ROMs, so for example a Galaxy A5 is supported, while A6 and A7 used to be, but are no longer (!) supported. So if you bought an A7 for Lineage OS, you are out of luck now.
Of course it is also difficult to install Lineage OS itself. For most of us, it is probably at least possible. But there is no chance rest of the 95% of the world will ever do this. Indeed, I would also feel at least anxious to attempt it (alas, for my current phone no Lineage OS is available).
So this is great. You can buy a Samsung phone and get it preinstalled with a good distro. I am not aware this is possible otherwise, let alone for less than 300 euro.
Everyone who doesn't understand why this is better than "just install Lineage OS with microG" has some serious disconnect going on.
I am fairly incompetent with computers, but I don't think I could fork my own Lineage OS for my phone of choice. Therefore, having something preinstalled and actually supported is a serious selling point for me!
Edit: Additionally, they will offer a service for you to send in your phone to flash it.
I really like this!