That is the catch. I agree that there is lock in, I've experienced that, but in return you get unparalleled interconnectivity.
Plus you get 5+ years OS updates on iPhone and iPad Vs 2-3 years on Android, budget Android. And for the money, the cameras will be better than any budget Android and the CPU will be better for gaming. Plus there is a world of accessories you just don't get with Android.
As cool as it is to have split screen or an SD card on my phone, when I need to take a picture with friends/family and they always come out terribly because all Android's under €750 have shit cameras, then none of that matters. An experience I recently had. We tried 3 android phones and in the end the friend with an iPhone got the best shot and that one was shared on the group.
Super embarrassing for Android that 3 different phones tried to get a decent semi low light photo and couldn't but a year's old iPhone got a great shot with 1 click.