Why is there not a utility which builds lineage OS for different devices?

I've been using Ubuntu on different old computer hardware of mine, and it's wonderful how easy it is to install and how portable it is between different devices. I have an 8-year old Samsung Android tablet which no longer receives updates, so using the internet on this device is a security risk. I assumed that I would be able to install a non-manufacturer specific version of Android on my tablet, and that this would be comparatively easy as installing Ubuntu on a computer. So I had a look around and I found lineage OS, and I was surprised to see that it's very much device specific (and unfortunately for me there are no recent builds for my device). I did a little reading into why this is, and I've understood from this that there are two main reasons why it's not to possible to install a single version of lineage OS on many different devices, and that the builds must be device specific. My understanding is that firstly the machine language that processors use varies more across Android devices than it does in desktop and laptop CPUs, and secondly that SoC architectures do not come with a BIOS, which is necessary to inform the installer binary what hardware exists on the chip. My question is about the second part of the problem to do with the BIOS; it seems to me that this is a straightforward problem to solve. I envisage a utility on my computer which recognises my Android device like how adb does. This utility could then get the hardware setup that exists on my device, either by directly interacting with the phone if this is possible, or by referencing the device's model number against some online database and downloading the information from there. The utility would then be set up to compile lineage OS based on the information that it now has about my device, and I can then copy over the device specific binary and install. That is, the compilation process is moved from a set of different developers who provide support for specific devices, down to a user friendly utility which builds a device specific OS. So my question is, has this idea been considered? I'm pretty certain this utility doesn't already exist, so then I would also ask, what are the main reasons that would make this difficult to implement? (and I guess I have a secondary question which is; have I correctly understood this problem? Perhaps I'm missing something in understanding why lineage OS builds are device specific. If this is the case, I would appreciate having this explained in more detail)