Both Visa and Mastercard, for example are structured by countries and by regions. Different countries and different regions have different rules and different fees. Cross-border and inter-regional transactions are associated with a lot of limits and many additonal requirements and complications.
All card schemes settle transactions in daily cycles. It always takes a few days for actual money to be transfered from one account to another. Crypto makes it happen much faster.
Transactional fees for transfers in crypto are much less than those of payment schemes. There is less infrastructure behind crypto, there are less people who run this infrastructure (as their job), so it is or at least should be cheaper to use it.
Decentralization is another factor. Payment schemes, being companies who run payment networks and provide access to them, make decisions and changes that affect all users of those networks.
And a bank cannot agree or disagree with this decision or change, it has to accept it and follow it. Payment schemes dictate the rules leveraging their position of an owner of payment network infrastructure. Crypto enables everyone to use payment infrastructure that does not belong to anyone, and because of that there is nobody who can limit or prohibit to use it, or who can set the rules that everyone must follow.
Accelerating the adoption of blockchain technology, which is the backbone of cryptocurrency, helps to ease the entirety of global banking. Essentially, it cuts out the middle-man, who is mistakenly entitled to a role that is unnecessary in the grand scheme. The “unregulated” world of cryptocurrency is really one of the most guaranteed and powerful processes in the digital age and enacts a better system to process payments.