Trading can be divided into delivery based or where you buy stocks of companies expecting the price to appreciate. Or else, futures and options trading where you are using derivatives to profit from either price change or volatility change.
Lesser than 1% of daily trading volumes come from equity delivery based trades. Delivery based trading is not zero sum game, we can all buy stocks of a company and all make money together if the stock appreciates. Similarly all lose money in case of recession when price drops.
Derivatives trading on the other side is a zero sum game. For every winner there is a loser. When markets are falling the person who is short (sold first) is making money and the person who is long (buy position) is losing. Vice versa when markets go up.
Yes 90% or more lose money, and 10% who are successful are making a lot of money . Also government makes more than 5000 crores just in STT alone, all brokerage businesses earn maybe around 2000 crores, all other taxes/exchange charges etc add upto maybe another 2000 crores. So almost 10,000 crores per year from traders go as costs.
You need to understand that F&O trading is like any other business, less than 1% are really successful at it.