in pakistan, desi means local
for indians it has a bit different meaning. The word is originally from Sanskrit, literally meaning from the country or of the country.
same same lol
now, it is our own cultural thing that we dont trust our local products and when we use the word desi for some products, at many occasions they are considered to be of low quality. But in few cases local products beat foreign products in quality and price. Like FT mentioned desi ghee. Other than that leather jackets, fans, knives and rice etc. are the products with which if you put the word desi, it symbolize them as good quality products.