Different people build for different reasons. A home built aircraft can be the equivalent of a tailor made suite. I wanted a new machine to my precise requirements, so I built a kit aircraft and fitted it out to my requirements. It would have been impossible to buy such a machine from a factory without spending huge amounts of cash. It took me 3 years elapsed / 1800 hours and £50k to build and I am very happy with the result. I fell in and out of love for the build, but I made the finish line and I learned a lot about airframes and engines, which you would not get out of a book!
To plans build you have to be very dedicated, with build times in the 10,000 of hours and decades to a complete aircraft, but this can be very inexpensive.
A home built can be operated at a fraction of the cost of a C of A machine, with a typical yearly saving on maintenance alone of £4k.
Rod1
MCR 01 G-KARK