It depends on how much you have there, I'd recommend if the amount you're storing on the exchange exceeds 10x the price of a hardware wallet, you're probably better off getting one.
If you have a smaller amount of funds you can also make a wallet with electrum and store your funds there (electrum.org - their wallet also works quite well with ledger and trezor).
We can't know for sure but a lot of things can happen:
1. What if the exchange closes and you're out of the cryptospace for so long you lose your funds due to that.
2. The exchange could lose money due to a hack or poor financing.
There's always a risk with leaving funds on an exchange but there might also be a risk in entrusting yourself too.
I'd say ledger and trezor are the best warm wallets (cold wallets have no online interaction and require it to remain secure).