Yes, I think fewer people are buying as many stand alone basic monitors as the past because laptops, Netbooks, Tablets, eReaders, Smartphones, Smart TVs/Displays, handhelds, and All-in-one computers like the Apple iMac already come with built-in monitor which are built-into the devices.
Plus, some TVs also let you plug your computer or laptop into it to use the TV as a external monitor to watch video, or to use software on it like a regular basic monitor for PC.
I agree, most people use laptops these days, and Tablets like the iPad and Smartphones like the iPhone are very popular, so fewer people need a separate monitor to watch stuff since they already have one on their device.
Also, I think a lot of people have older monitors or know someone who has one which still work from old desktop PC, so there is less need to buy a stand alone monitor when they can use their old LCD or tube monitor.
My LCD monitor is over 5 years old, but my monitor was used, so the previous owner probably owned it for a few years before he sold it for me for a cheap price.
I agree they last pretty long as long as you don't drop or punch them out of anger.
Those Tube monitors also last pretty long. I still have tube monitors and TVs which still work.