Can't we skip creating "internal transfer account" and directly create an entry like Cash ac..dr , To Bank a/c while withdrawing cash from bank. Is there any other way? Whereas by creating an internal transfer account in the default accounts under settings solves the error of "missing required account in accountable line", I do not want to put the money in internal transfer account so far. Please help me.

When there is an Internal Transfer, there are two things to reconcile - the withdrawal from the first bank account and the deposit with the second bank account. Odoo needs two Journal Entries for this to work, that's the reason we use the Internal Transfer account. Changing this would require customization and would provide no real benefit. Odoo is designed so that only amounts verified by bank reconciliation are posted to the GL account representing the bank account, to keep your data at the highest level of accuracy and integrity, so manual entries are discouraged because of this.