there are many reasons why some people invest more in bitcoin than in real stock markets, such as public valuations of real stock markets that no longer give confidence. they are more profitable than providing wealth to their customers.
so because that many people who prefer to invest in bitcoin. because it is trusted, simple, and certainly promising.
Though investing is quite risky, investing in bitcoin is a very good thing to do nowadays (for risk-takers only) because the value gets higher and higher as days passes by. Bitcoin has many potentials and very promising to become a future money. More benefits you can earn from more secured assets.
Invest wisely and beware of scammers.