Why paypal checkout asking buyers to create an account?

I want that buyers should pay easily without much formalities, how i can remove fields to create a paypal account while buyer in paying. 

I did check your last edited form "Responsive Paypal Payment Form" and found that you have added Paypal Standard payment tool. Please note that after form is submitted, users will be redirected to PayPal checkout page to submit payment. They can complete the payment using credit card or their own Paypal account.

I did test your form by sending a test submission and it does not display any option to pay using credit card. Please check the screenshot below:

Please ensure that PayPal Account Optional is enabled in your account for guest and credit card payment. You may like to take a look at the following guide which should help you: https://www.paypal.com/us/webapps/mpp/account-optional

Hope this helps.

Do get back to us if you have any questions.