There will be a time you will get lazy about going back and forth from the trading platform to the wallet. I recommend having a habit to do it, that way it will be added to your own system if withdrawals are needed to happen.
Trezor would be the best investment you could ever make. It's not like there's an expiry for it or if they close down all your coins will be gone. They can still be accessed as long as you have your 24-word recovery phrase.
An investment for better security which all crypto users are dreaming of as we are always prone to attacks being online.