Why hold a wallet?

Hi everyone!

I am just beginning to enter the Crypto/Bitcoin space. I have opened a Binance account and understand how to fund it.

Naturally, I want to ensure security in the event my modest investment in BTC does reach the heights we all believe of being possible.

I plan to purchase coin and hold for the L.T, while also moving small portions into Altcoins that have projects I support. I am getting familiar with staking and likely will pursue that as well.

My main question is, if I plan to buy and hold is it safe to just hold within my Binance account until the eventual withdrawal once I reach my price targets? I have read about hardware wallets, and specifically, TrustWallet. Even after reading their page, I am still not sure why I would move my Binance account into say, TrustWallet? Does it provide more security? Is it better for a Buy and Hold approach? Would I still be able to move small portions of BTC to ALT projects that interest me?

Sorry if this is a ‘noobie’ question, I am just puzzled, but want to ensure I approach this new investment environment responsibly.

Thanks in advance,