Mobile devices are becoming increasingly better hardened. App stores are helping by vetting apps to weed out malicious behavior. Servers are protected by sophisticated security systems.
In the end, the mobile apps themselves remain the most vulnerable elements in a modern application architecture. Once downloaded, they can be reverse engineered and even modified. They may contain or provide gateways to valuable assets, in-app purchases, hidden features or defects, and more, which organizations and developers need to protect.
Luckily, protecting Android and iOS apps has also come a long way since the early days of name obfuscation.