Why a convertible loan?
With a convertible loan, you postpone a discussion about the potential value of your company. Because your company is still young and there are few data points to make a real value calculation, valuing your company is difficult and the point of views of you and the investor will often differ. With a convertible loan, you delay this discussion into the future, when more data is available.
In addition, you avoid discussions about shareholders' rights and obligations, and the terms of the convertible loan are straight-forward. This allows you to get started growing your business faster.