The original bitcoin whitepaper is focused on avoiding double-spend of digital cash, facilitating non-reversible transactions in a way that's not vulnerable to collapse or suborning of the central counterparty. It has the following statement in its introduction:
"Completely non-reversible transactions are not really possible, since financial institutions cannot
avoid mediating disputes. The cost of mediation increases transaction costs, limiting the
minimum practical transaction size and cutting off the possibility for small casual transactions,
and there is a broader cost in the loss of ability to make non-reversible payments for nonreversible
services. With the possibility of reversal, the need for trust spreads. Merchants must
be wary of their customers, hassling them for more information than they would otherwise need.
A certain percentage of fraud is accepted as unavoidable."
(No solution is offered for the merchant defrauding the customer, which is the business that ebay was built on solving)
But with non-reversable transactions, you still have the trust issue. Now it's that the customer has to trust the merchant, that they're not going to completely rip them off.
"Completely non-reversible transactions are not really possible, since financial institutions cannot avoid mediating disputes. The cost of mediation increases transaction costs, limiting the minimum practical transaction size and cutting off the possibility for small casual transactions, and there is a broader cost in the loss of ability to make non-reversible payments for nonreversible services. With the possibility of reversal, the need for trust spreads. Merchants must be wary of their customers, hassling them for more information than they would otherwise need. A certain percentage of fraud is accepted as unavoidable."
(No solution is offered for the merchant defrauding the customer, which is the business that ebay was built on solving)