You mean creating the generator with a deterministic seed is shorter code than creating it with entropy? Well yes, because the entropy source is std::random_device so it's an extra line for an extra variable.
Don't think it's a problem in practice because every online tutorial or Stack Overflow posts contain that multi-line snippet for real entropy. C++ programmers are somewhat used to verbosity anyways.
> You mean creating the generator with a deterministic seed is shorter code than creating it with entropy?
No, it was more like: it's easy to write code that appears to fully seed a RNG with entropy, but in fact only seeds a tiny part of its state. Making it seed the whole lot, especially in a portable way, is surprisingly hard to get right. But I now can't find the article that explains this.
I seem to remember I had to use Boost.Random instead of the C++ standard library to do this in a real program, but this was a few years ago and the latest standard that was available in most implementations was C++11. Perhaps things have improved since.