electromagnetic radiation - How come Wifi signals can go through walls, and bodies, but kitchen-microwaves only penetrate a few centimeters through absorbing surfaces?

The only difference that I know of between kitchen microwaves and WiFi signals is how much power is pumped through them.

Why is it that WiFi signals, being 1000 times weaker can travel so much further, while something like a concrete block can absorb $1000 \, \mathrm{W}$ of microwaves from a kitchen magnetron being blasted at it? Or am I mistaken about the materials that WiFi signals can pass through?