The author went with an UG nested in a KG as the legal structure. That's two legal entities. It's a neat workaround to avoid corporate taxes (the KG acts as a pass-through vehicle, for taxes and for liability), and avoid personal liability (which passes through the KG but stops at the UG).

In comparison, AG and GmbH also shield their owners from liability, but require capital deposits and are subject to corporate taxes.

Going with a UG-in-a-KG is an exercise in eating your cake and having it too. It's a cool legal structure that works around some of the limitations of its building blocks. It shouldn't come as a surprise that the people who can build the neat hack for you are going to want to get paid in order to do that.

No it’s not the most complicated form. They didn’t go for a standard GmbH. A simple GmbH using a template protocol is simpler and cheaper