[ilaksh]

The first reason it is necessary is that the actual secret is revealed so the transaction entirely relies on trustworthy parties.

[_aavaa_]

What secret are you talking about?

What do you do if the other party does not hold up their end of the bargain after they received the money??

[ilaksh]

The credit card number lol.

That's a different issue. First issue is much more primary.

[_aavaa_]

A credit card transaction does not in principle have to send the credit card number to the vendor (e.g. Apple Pay already does this).

But a crypto transaction in principle does not allow for charge backs since transactions go one way.