Android is a ubiquitous OS which has precisely the value and worth attributed to it by Google when they give it away to any old schmuck. iOS is locked down and ACTUALLY SECURE, and when one knows how to use one iPhone, one knows how to use all of them.
It depends on how you define "secure", what tools someone uses etc...
Both iOS and Android are exceptionally secure for the average user, provided you use a strong passcode/PIN and don't install anything dodgy (and yes, malicious software exists on Apple devices too).
If you're using a 4-digit PIN, expect that to be cracked or bypassed immediately, if not, within minutes on both Apple and Android* devices. There are caveats however. Some of the more obscure Android devices are extremely difficult to break into, even with an insecure passcode. The later versions of the Google Pixel's are also not very well supported from a security researcher's standpoint.
There is no point in debating if Android or iOS is better.
Every user has there own preferences on how they want there device to work. So for some kinds of people Android is better suited and for some iOS is better suited. Just use what you think works better for you.
Each has its own strengths and flaws. My own preference is Android, but i can see why some people would prefer iOS.
Exactly. Neither is "better", they are just suited for different use-cases. It's like arguing whether Linux is "better" than Windows... it just depends.
Personally, there are things I just can't do on Apple devices, so that rules them out entirely for me.