If you plan to sell or exchange your coins over the next few years, experience shows that storing coins in a cryptocurrency exchange account is no different from storing them in a wallet. And in many ways it's even more convenient.
Wrong.
Only if you own shitcoins that you want to sell in the
next few hours to days it makes sense to store them on the exchange so that you can act quickly considering how shitcoins pump and dump very quickly.
Otherwise if you own bitcoin and you want to keep it for
years it makes no sense to store it on exchanges, they may not even exist in a couple of months let alone be around in years!