Honestly I actually attribute at least a bit of it to MKBHD himself -- he's got huge hands, and he makes large phones look manageable. He's one of the most important tech influencers out there and he makes a 7" phone look like a 5" phone.
I have about average sized hands and I had to do weird juggle-shifting to reach the far side of my old Galaxy Notes. I'm on a Sony Xperia something or other now, which has a narrow but taller screen, and it's a bit better -- but still not ergonomic.
Look Ma, this guy says it's ok that I'm a full stack dev. He says it's even good!
Also: counterpoint: if you teach your kids to code, you can outsource to them.