How exchanges/brokers/traders of non-crypto "stocks" have not invaded crypto platforms yet?
Crypto usually generates better profit (and better chances) than most stocks.
How people who live from stock-trading (e.g.: companies) have not invaded crypto yet?
(If we look at communities' sizes, their size is much-much larger)
There are some individual traders who have ventured into crypto trading.
Companies are usually more cautious - the risk/ volatility associated with crypto is very high.