Yes, I think in the future most small desktop computers cost less then the monitor since you can't shrink a monitor too small since people need the glass to be a certain size to see it. Unless the price of glass also drops to a very low price because a lot of people are willing to sell glass cheaply.
A computer can be very small, and cost very little to make because it uses less plastic, metals, and chips like the Raspberry Pi computer which only costs £15 which is about 30 dollars US.
Indeed, there are mini projectors which cost under 100 dollars for connecting to Game consoles, Computers, and DVD players at Walmart, and other store, but the quality of the image is not very good, and you need a dark room to use them since the brightness is not very bright when a Window is open, or the lights are on.
A lot of people these days are also using their TV as their monitor since newer computer has HDMI ports like the PS3 for connecting to HDTV, so some people who own PC and laptop just use their HDTV to use as a monitor.
I think most of us prefer small monitors because of the space savings, but when you are in your older years like 50s or older a bigger monitor would be needed if your eyesight gets worse.
Older YouTube videos taken with older cameras would look crappy, but newer YouTube videos recorded in HD 720P-1080P or even 480P resolutions will look good since 720P-1080P is like PS3 Xbox 360 Quality Video and 480P is like Wii PS2 Quality video.
A huge monitor would be good for watching videio which you downloaded, and for playing Full Screen PC Games.
You can also make the monitor image smaller when you are on forum by adjusting the horizontal and vertical width of the monitors image in the control panel for the monitor.
and then I would wish I had the space to put that huge monitor somewhere 