What is important in your opinion when choosing a platform for yourself? What is worth paying attention to?
First point would be the platform's reputation. You don't want to go where there are problems or high delays in handling various issues, including the deposits and withdrawals.
Then the liquidity on the trade pair you want should be at reasonable levels.
The fees - trading and also deposit/withdrawal - are quite important too.
After this I think that's all personal choice. Some prefer the ones where KYC is not needed, for example.
You should also be prepared to see a lot of annoying trading bots wherever you go. In some places they may be more or less annoying, you'll have to look around for yourself.
To add from the above pointers, I prefer exchanges with fast response of technical support. Like for example, if you have withdrawal problems, and you contacted them, at least they have reply within 24 hours, if it will be days or weeks, it is like you are waiting in vain. Liquidity is also important when you are trading. You should check that before sending any coin to that exchange because you might end up waiting for days just to trade a particular coin. And finally, once you have finished your trading, don't forget to withdraw or transfer your funds to your secured wallet. Even if the exchange is popular like BNB, it is always better not to leave your coins in an exchange.