The difference is that a GmbH projects your personal assets. The risk for a software engineere is small, much smaller than for a lot of other business but still it protects you.
It also makes you a better business partner (in theory) as you have crossed a certain amount of effort to create a GmbH
I also createda GmbH in germany and i tell you a thing: I don't care to optimize every single shit for the optimum. If i would, i would go to USA and accept that the social scissor is so crazy wide that not every USA citizen can't just go to a dentist.
I live in germany, thats how it is and i'm fine with it.
It also makes you a better business partner (in theory) as you have crossed a certain amount of effort to create a GmbH