That's an excessive number. Great laptops can be had for under $1000.
Obviously, you could spend over $4000, but I don't think this is a reasonable number for most people. Even most 'computer' people. And who still buys tablets anyway?
Q1 2018 13.17 million Q2 2018 9.11 million Q3 2018 11.55 million Q4 2018 9.67 million
I think a few people still buy them...
So if you spend $2500 on a MacBook Pro, $800 on an iPad, and then $1000 on your iPhone, boom, you're over $4000.
$4000 doesn't go very far.
I do. I find them quite handy (I own 5 right now), although I admit that I use them as special-purpose devices rather than for general purpose use.