Mobile device statistics states that Android dominates the mobile operating system with 70% market share while Apple has only been at 30% or lower. Both the operating systems have been available for almost the same duration and still Android continues to take the lead. I believe, this trend will continue and the gap between the market share isn't going to change any time soon for many reasons. Let's look at some of the compelling reasons why people choose Android instead of Apple.
I use both Android and an iPhone but I have entirely different uses or purposed for each of them. My main phone is iPhone and all experiments are done in Android device.
Android ecosystem is not tied to a hardware vendor, it is open source. So there is a bunch of hardware players in the market which ensure competition. When there is competition, the benefit is to the end-user because of the competitive price point. Today you can pick from Samsung, OnePlus, Google, and other vendors when it comes to android phones.
On the other hand, apple's ecosystem is a closed ecosystem and only Apple manufactures the iPhones. So there isn't quite a lot of options to choose from.
The android world offers low-end, mid-range, and high-end phones that suit the budget of all types of consumers. When it comes to Apple, the price point is a huge deterrent. Especially in countries like India, you can't think of an apple phone without shelling out 50,000 Rupees at the minimum (~670 dollars). Apple sure must hate us! Apple sells iPhones at much lesser costs in the US, UAE, and HongKong, etc. I know people used to get their friends to buy these devices when someone visits that country.
You can pick up an android phone for as low as 15,000 Rupees (~200 dollars). You get the same mobile operating system as on some of the flagship Android phones, even in this range of devices. So the experience remains, only performance and quality changes according to the cost. This is a great advantage. Considering, you are paying a lot less. Still, there isn't a taxonomy when it comes to features that are available to you.
As I said, Apple built an ecosystem and the advantage is tighter privacy and simple to use feature set. However, it is locked. You can't fancy installing anything on an Apple device without voiding your warranty. It is very unlikely that most of the population would want to pay for all the applications that they use. If you look at Apple's market store, most of the good ones are paid. Don't get me wrong, I am not advocating for free applications. Strictly talking about the affordability factor here.
As opposed to that, Android has an ocean of applications in PlayStore itself. If you want to pick and chose other applications which are not in PlayStore, you could still install them. Not just applications. You could change the entire operating system itself. There are forums and people are coming up with optimised and efficient versions of operating systems that are cross-platform compliant. This is the freedom that you get from the Android ecosystem.
If Apple were to reduce cost of their devices, even more adoption of ios will happen. It is not like Apple spends a lot of money on making a phone. Just that they consider it to be a flagship and the costs are beyond the ordinary people to afford.