I understand that creating a debit card in a decentralised market would take some figuring out
no you don't understand
I feel like you don't know what is a blockchain
a lot of new people interested by cryptos have no technical background and don't understand what blockchains are for, what blockchains make possible, and what is the difference between a blockchain-propulsed service and a traditional service
it is
strictly impossible to use MasterCard or visa or any other existing credit card provider in a decentralized way
it is thus stupid to create a blockchain for this
tenX, Monaco and all other coins in this field simply abuse the lack of intellect of the people
there is already dozen of bitcoin debit cards service,
they do work since years:
https://bitcointalk.org/index.php?topic=1242788.0you can not decentralize debit cards without creating a new card processing system and thus needing to make special ATMs and Point Of Sales all around the world
and guess what, the banks won't replace all the ATMs to make decentralized debit cards possible. that would be suicide for them. nor government will support uncontrolled access to their currencies