If we are careful about fee rate, transaction fee and don't want to overpay transaction fee, checking mempool before pick a fee rate for our transaction is what we have to always do.

Wallets might have their inaccuracy in transaction fee (fee rate) estimation and suggestion and we must double check their estimations with different options.

• Minimize your transaction fee with Electrum wallet
• In Electrum wallet, mempool is the best option if we need to choose one default option for transaction fee estimation.