There are significant percentages of people in China and India that have never used the internet on any device at all, let alone opened any PDF.
The number of people filing taxes on a computer in India rounds to zero. For example, a quarter of India is illiterate. And 97+% of them don't make enough money to owe tax. And of the final 3%, many have someone else file for them.
https://www.ibtimes.com/how-many-people-india-pay-income-tax....
The linked article is 10 years old, and the situation on ground has changed a lot, specifically due to concentrated efforts by the central government to prevent tax evasion. I'm not aware of the figures, and a majority chunk of income-earners still doesn't pay income tax, but it's most definitely much less than the 97% that you mentioned.
Tax evasion as I know it, and as has been informed to me by many financial consultants I've talked to, is now increasingly difficult. You really need to have back-channel contacts with the right people and spectacular know-how of the loopholes to pull it off. I'm talking about large-scale evasion here, but much of it stands true for small-scale as well.
The number of people filing taxes on a computer in India rounds to zero. For example, a quarter of India is illiterate. And 97+% of them don't make enough money to owe tax. And of the final 3%, many have someone else file for them. https://www.ibtimes.com/how-many-people-india-pay-income-tax....