Currently, the bitcoin withdrawal fee on Binance is close to $13 worth of bitcoin, which is very high compared to what you will be charged if you buy from Dex, and you can move that directly to your personal wallet.
Good point and this should be taken into consideration when buying Bitcoin from CEXs, especially when it's a small amount. Imagine buying $50 worth of Bitcoin on a CEX and paying $13 dollars in transaction fees to withdraw to a personal wallet. On that note, I'd suggest op uses CashApp to buy Bitcoin if it's available in his or her country because CashApp does not charge withdrawal fees, the transaction is processed in batches.