Yes. Of course having more icons will slow up the computer. It will seriously gets slow when you start up your computer.
Number 1 mistake.. if you have too many icons, it wont just slow down your computer, it is HARDER for you to locate things!!!
Icons are made as shortcuts. If you have so much icons on your dekstop, what is the whole point of having shortcuts? It is not even called shortcuts if it takes people 2 minutes to locate the program that they want to click on. People just abuse the purpose of having a desktop for “shortcuts”.
So all I am saying is have the icons that you really need. The programs you mostly use should be on the desktop. Nothing else.