There is a difference between losing data, and losing transactions. Transactions can be replayed from the message log (depending on the implementation) and reprocessed if needed.
I have seen plenty of recovery operations in finance, sometimes cases where the entire database server was lost, and even though the transactions were not saved, no actual financial data was ever lost, as this data could always be reloaded.
Of course, certain systems exist that do store data in a way where loss is not accepted, but even in finance these are somewhat rare compared to the vast number of other systems.
I have seen plenty of recovery operations in finance, sometimes cases where the entire database server was lost, and even though the transactions were not saved, no actual financial data was ever lost, as this data could always be reloaded.
Of course, certain systems exist that do store data in a way where loss is not accepted, but even in finance these are somewhat rare compared to the vast number of other systems.