1) It really depends on how you use it and sometimes there's also an element of luck. But in general, Apple products are long lasting. I have two Apple products that are more than five years old (an iPhone 6S and a MacBook Air), so yes, it is possible.
2) Honestly, there's nothing so great about it except if you use multiple Apple products and you have close family and friends who do too, then you'll appreciate the seamless integration of all the products.
3) Don't use Spotify or Apple Music yet so can't comment on this point.
4) Yes, in my personal experience, Apple's camera output produces more life-like colours but it could be a matter of personal preferences - some people appreciate the livelier and more vivid colours from Samsung or Huawei cameras.
5) Don't see how one backup can be better than the other. In terms of ease and speed? I think it's more or less comparable although I have to admit I don't use Google Drive as much.
6) This will be based on your usage, if you're a heavy user then the bigger the battery size, the better. Unfortunately for the 12 series, Apple has reduced the battery sizes across all models vs the 11 series, so moderate usage might be able to get you through a day, but it's not going to match the Android phones with 4500mAh batteries or larger.
Need to manage your expectations bro, or you might end up disappointed and swear never to touch an iPhone ever again
Surprised that i still saw a number of peoples in my company using iPhone 6 & 7, that really made me doubt whether it's true that the phone really can last that long. The only issue they have right now is that Apple no longer support iPhone 6 or older phone, so they also planning to change.