E-Learning ≠ Instructional design
E-learning (and especially the apps) is a tool. Instructional design is a process. The way you've formulated the question is the same as asking: If textbooks can be found in the library, does it mean that teaching is no longer necessary?
Instruction design has existed for as long as teaching has existed - even digital technology hadn't even been imagined yet.
ID answers the question: What is the most effective way to teach a concept to a particular learner audience? To answer this question, the instructional designer first needs to know how people learn in terms of cognitive processes and neuroscientific findings. And only then comes the how, or the tools, such as e-learning, in-person learning, or a combination of methods.