Ask HN: What makes BlackBerry phones more secure?

I've been hearing on the news they are wanting Donald Trump to give up his personal cell phone. That he'll most likely get a modified BlackBerry like Obama has. It seems like an iPhone would probably be just as secure considering Apple approves all the apps on it, plus Apple is big into encryption, etc. I haven't really used Android, but I'm sure they're similar measures Google would put in place. I think they automatically scan apps instead of human reviewing. So 8 years later, I'm curious why they think Blackberry is more secure. I know I'd hate having to switch to a completely different phone compared to my favorite if it was me. Also curious why they never talk about the President or President-Elect giving up their personal laptop too. As far as I know he uses a MacBook Pro from some photos that came up around the time he was talking about boycotting Apple.