I would say it depends on your value of funds and your view on trading or investing.

If you are holding small amount or big amount of coins and if it is for purpose of long term hold then you should keep your funds in wallet after making successful transaction in exchanges. Otherwise you will be in risk to lose your funds in hands of hackers.

If you are holding small amount of tokens and you want to trade frequently then it is best to keep in exchanges even though exchanges are risky to keep your funds because for small amount the fee for withdrawl and deposit itself takes significant portion of your funds.

And finally if you are holding huge funds and you want to trade then transfer the tokens to exchanges when you want to do trade exactly and after completion of the trade, it is better and good to transfer your funds to your wallet preferably cold wallets for your funds safety.

Depends on how long do you want to hodl your coins and which exchange are you using.But every veteran in crypto will tell you that wallet is safer and better thing to do.

I keep on exchange only those coins that I trade.
I keep coins for a long time on my wallet. Because I do not plan to sell them.

Keeping your coins in a wallet is a safer option than keeping all you assets in an exchange. Exchange can shutdown anytime on the other hand wallets are secured by private key which is a safe bet.
The best part about wallets is that you can use any method to access it. It could either be a hardware wallet or websites like myetherwallet.
I never keep anything on exchange in fear that they might run away with all of my belongings.

Actually everything is good when we do it carefully, when we are careless either in exchangers or wallet still prone to theft either in terms of password or private key

if you store coins/tokens on the exchanges, you don't have the private key, which mean you don't have the right to control your coins. the number you're seeing just are made up, but it's very fast in trading, and I think nowadays. exchanges are become more reliable than ever, so an cold wallet is not really necessary with people have little money like me

for now I prefer to keep it in Exchange because the price is still changing and I'm sure the price will rise again. but if you want to keep it in the wallet, I think it is a good choice too. it all depends on each taste

Fo me, If you want your money to rise  then It is better to save it on exchange because it is profitable but sometimes its too risky, also if the value of your holdings change at the lowest point... the value of you holdings changes depends on the flow of the market.

In my experience, Wallet is better for holding and moving altcoins, The exchanges charge high fee for moving coin between wallets.

I would like to suggest store your tokens that potential to survive in crypto more years from now in hard wallet. For me it is more safer than other although you have your own risk by taking care your wallet.