The problem is that when a final binary is linked everything goes into it. Then, after the link step, all the debug information gets stripped out into the separate symbols file. That means at some point during the build the target binary file will contain everything. I can not, for example, build clang in debug mode on my work machine because I have only 32 GB of memory and the OOM killer comes out during the final link phase.

Of course, separate binaries files make no difference at runtime since only the LOAD segments get loaded (by either the kernel or the dynamic loader, depending). The size of a binary on disk has little to do with the size of a binary in memory.

> The problem is that when a final binary is linked everything goes into it

I don't think that's the case on Linux, when using -gsplit-dwarf the debug info is put in separate files at the object file level, they are never linked into binaries.