As child, I once dreamt about taking a bath inside blank CD-R’s.
Is it theoretically possible to manufacture blank discs at home?
No high quality needed. Even CQ (crappy quality) media would be great.
Definitely not possible. You would need expensive and complicated manufacturing machinery, supplies of special raw materials and a class 1000 clean room.
Second hand machinery can be bought for 1/20th of the original price or even less (due to decling state of the optical disc market):
Low quality CDs are good enough.
I enjoy using CQ (crap), as already stated earlier.
It is impossible without the proper equipment and materials.