“Yes,” said Arthur, “yes I did. It was on display in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying ‘Beware of the Leopard.’”
Keep in mind that this is a trade-off, it requires more computational power AND battery, so giving users access to the leavers makes sense (e.g. power users with nice equipment can pump up the number).
That being said I do agree that it is up to the vendor to set AND enforce a new higher minimum. If someone logs in with 5K rounds, it should be changed to the new default (100k).
On a related note Bitwarden also allows users to configure this. I recently increased mine to 150K rounds.
99.9%+ of people aren’t that technical person. Safe defaults need to be used and kept up to date for them.
Ideally they'd manage that number and prompt the user to change it over time.