iPhone sales are slumping and Tim Cook thinks it's the fault of the users: They are not switching to newer models. 

Source: NY Post

If you don't own the latest model of iPhone, you might as well use an android phone. Apple, as a company, has cashed in on this for the longest time. 

Before they were busted. 

Source: 9To5 Mac

A few months back, it was revealed that they allegedly deliberately slow down the phones so that people switch to newer models. 

Apple clarified it was to avoid 'unexpected shutdowns'. 

Source: BGR

No one bought that. They bought new batteries instead, after they were made cheaper for redemption. 

The company offered battery replacements at a discounted cost for anyone using iPhone 6 and the versions released later. For one year. 

Source: Cult Of Mac

Now, the customers are content and iPhone sales are going down. 

According to reports, Apple revenues for the first quarter have been lowered down from $89-$93 billion to $84 billion. 

Source: BGR

The biggest defaulter is Greater China, as per Cook, with local brands like Huawei seeing a rise in sales.