Tents were so expensive in the late 1970's that I made my own, the first was a minimalist transverse ridge tent suitable for winter use (separate flysheet and inner), which I used quite hard for a few years when I worked a long summer season on the buses then toured on the bike in late autumn/winter till I ran out of money.
I made another, slightly bigger tent in the very early 1980's for two-person camping, this has had less use but ended up failing due to the materials ageing.
Absolutely not worth doing that nowadays, the cost of materials is already more than the price of a reasonably decent lightweight tent.
The same applies for most other textile objects. I used to make my own pannier bags, saddlebags and other bags. Plus bike and hiking raingear.
The only things I have bothered making recently are lightweight rain capes for hiking (very quick to make, lighter and better quality than those I have seen advertised) and very specific bags that aren't easily available commercially.