A huge problem is that commercial exchanges are small low profit companies, whereas investment exchanges are making much more money, so some commercial exchanges are turning into investment exchanges. Kraken did that to give an example.
May you share more information about the Kraken changes from a commercial exchange to an investment exchange, please.
A commercial exchange is just like the currency exchange booth you find in all international airports. You exchange one currency with another. That's it. It's quick and safe.
You named investment exchanges like Binance and I know that you can exchange your bitcoin, altcoins to cash on Binance. Is it different from commercial exchange?
Quick but safe or not, it will depend on your trading with your trade partners.
Use investment exchanges at your own risk.
If you don't own your private keys, it is always risk on any exchange.