Yes, that's true however there is always room for error which is why accountants and business owners balnce their books or close their books. Your books are "balanced" or closed when the bank accounts and credit cards are reconciled and any adjusting journal entries are made. In a nutshell balancing ensures the accuarcy of your financials:)
I do all the reconciling for ours but our accountant does go over it yearly and balance and make sure everything is right on. One thing that I like is organization so I try to make sure it is always organized throughout the whole year. Makes it easier and faster at the yearend.
For my large activity accounts (like checking) I try to reconcile monthly but I went through 7 months this year and when the Accountant's Copy was uploaded all those reconcilations went away and I had to do it all over again. It was a good exercise in making sure I did get all transactions entered but...
Loan accounts get reconciled at least once a quarter (editing the memorized transactions that posted to account for principal and interest)
And for one client the ability to add and edit has gone south with their bank no longer able to conncect to download - I now have to wait until month end to update.