1) I mean, also great for anyone who sells stuff on places like Craigslist, where the recommendation is to take cash? Taking the standpoint "the consumer is always always correct and refunds should be trivial" sort of works for larger companies that can amortize scams, but you enable a different form of crime (fraud) by adding that feature to small-scale transactions. Hell: many of the modern payment rails you now have to use to buy stuff from vendors at fairs don't have user-accessible refund mechanisms, including Zelle.

2) To the extent to which you really want those features, they are no different than any other in their ability to be built on top of a decentralized database, but now can be done in a way where the rules can be open and anyone can experiment: as an example, you could put your funds into a smart contract that only can transfer money to other people through an escrow mechanism which holds onto the funds for a net-30 period and pays a small fee to the protocol; you then could have the people who own the protocol governance token (and would receive the fees) vote on members to sit on a refund arbitration council (which needs to be somewhat fair or people will stop using the network, crashing the fees they are paid, aligning the incentives in a similar manner to a centralized business doing the same).