I really appreciate you for taking the time to post your concern here in the Community, @zodgevaibhav. 

Let me share some information on how QuickBooks Online banking works. 

In QuickBooks Online (QBO), we can create rules that automatically categorize transactions. When you set up a bank rule, you no longer have to look for a match on your bank feed transactions manually. The more we utilize bank rules, the better it gets as categorizing. Here's how:

1. From the Banking menu, choose Rules. 
2. In the upper-right corner, click on New Rule.
3. Fill in the required fields of the form.
4. Set the rule conditions. You can set a single rule with up to 5 conditions. Set and include the following, then select + Add a condition.
5. In the Conditions fields, specify whether the rule applies to Description, Bank text, or Amount. Then select Contains, Doesn't contain or Is exactly to decide how QuickBooks applies the rules.
6. At the bottom, ensure that Automatically confirm transactions this rule applies to is turned on. 
7. Select the settings for the rule. Select the Transaction Type, Category, Tags, and Payee to apply.
8. Click on Save.

QuickBooks automatically applies your rules to transactions in the For Review tab. These are the ones you need to review every day.

Also, in QBO, there are cases where some of the transactions can't find their match from existing records. You may click on this article to know the possible reasons: Find out why there are transactions that don’t have a match.

Additionally, I've included an article that will guide you in case you want to categorize your banking transactions in the future: Assign, Categorize, Edit, and Add your Downloaded Banking Transactions.

Should you need any additional assistance in matching your bank transactions, I'm just a reply away.