both have benefits and issues but at a broader perspective i believe for technical people like those who are aware of security issues with apps and their permission and malware stuff, and know how to handle them and have all comforts of customizing and getting what they want done android is best for them but for naive users who are happy with what company gives them and those who rely on company for their security ios is best for them.
At the end it depends what a customer as individual really wants
They both have interesting features, and numerous differences. Some of the differences in these devices are a result of their manufacturers rather than purely operating system related. One of Android's potential disadvantages has been fragmentation of many different versions and editions out on the market, similar to Linux, but this has not proven to be a great problem. If you are interested in paid apps (education or gaming), IOS might appeal to slightly more. In general, when it comes to new features, Android usually introduces them earlier than iOS. If you are technically savvy and interested in frequently configuring or tweaking your device, the operating system and other features, Android will appeal to you. Android has the higher market share in the consumer world but the enterprise / business environment is still hotly contested (so it depends on your company, and your industry).
In my opinion this question could be answered based on ones preferences. Since both systems have their own advantages, Customer may prefer one to another based on their needs. I personally prefer Android for flexibility and openness and variety indeed.