There are too many scams in crypto. Coinbase is a trusted exchange and easy to use. Passing regulation means they less likely to lose investor funds, same as Gemini.
the only problem I see in them is that people from my country can not buy or sell on the coinbase
Buy and sell is not yet available in Mz Mozambique. Sign up for updates
they support a very small number of countries:
COINBASE IS AVAILABLE IN 42 COUNTRIES
and it seems that this number is not increasing