Because it is treated as a close task. Four weeks of transactions are matched in one sitting, by which point nobody remembers what a payment to an unfamiliar name was for.
Bank reconciliation matches lines on the bank statement to postings in the ledger, leaving a short list of things that genuinely need a decision.
The bank feed brings lines in daily. Rules handle the repeats — same vendor, same reference — and the rest is suggested by amount, date and counterparty for a person to confirm.
A customer pays one invoice in two transfers a day apart. Both lines match to the same invoice and together settle it, so it clears instead of sitting part-paid.
It will not invent the reason for a payment. An unexplained debit with no reference waits for someone who knows, which is safer than a plausible guess.
Matched lines confirm the posting, clear the invoice or bill, update the cash book and feed cash flow actuals. Unmatched lines stay visible until somebody deals with them.
Yes, once you confirm one. You can still require review above a value.
Matched to the accounts you nominate, usually by rule.
Yes, by importing a statement — though feeds are what make it daily.
Fourteen days, every module, no card. Or half an hour with someone who will run it on your own records and tell you where it does not help.