Biggles78 is your prime example of someone jumping on the apple bashing bandwagon who has absolutely no clue about what they are talking about.
8gb to 16gb upgrade costs around 160eur, not exactly expensive.
As for anyone who talks about apple being a "walled garden". That's more absolute trash. Anybody can write software for apple, you can use plain old c/c++ if you don't want to use apple Developer tools. Nor do you need any approval from Apple.