[tapland]

Components are not wasted or used up by being soldered to a board.

[cerberusss]

In a lot of keyboard designs, you'll solder an Arduino Micro Pro to the PCB. It has, I dunno, 18 pins or something. Without a professional desoldering station, it's almost impossible to remove. I tried with desoldering braid, wick and pump but still managed to damage the Arduino. A more experienced person tried with a heat gun, also damaged the Arduino.

[pjc50]

They certainly can be if you're not very good at desoldering. Especially BGA parts which require laborious re-balling for reuse.

[tapland]

Luckilly you won't be installing BGA parts to begin with using a soldering iron at home.