Software Engineers build the tools, so I feel it shouldn't be surprising that one of the first areas it's being applied is the domain it's inventors are most familiar with.
SWE happens to have a massive training corpus readily available online, and is something that is done entirely with text.
For other engineering disciplines, the data is much thinner and the methods tend to be heavily visual, i.e. mechanical drawings or electronic schematics.
SOTA vision LLMs cannot read a schematic to save their life. The accuracy is <5%.