FYI - Banks do work with cannabis in states where it's legal. Those banks just can't be national banks - they have to be state ones that are regulated by the state. In other words, Chase/BoA/etc. can't touch it because they operate at the federal level and are highly regulated.
https://www.riskscout.com/post/the-state-of-cannabis-banking
As far as I can tell, the stuff the banks won’t touch is either legally risky (weed) or financially risky.
https://www.forbes.com/sites/afontevecchia/2012/07/16/hsbc-h...
(PayPal also cannot be used for cigarettes or porn, so they have a policy of avoiding what they see as high risk items, including items regularly handled by other card professors)
On the flip side Amazon will sell all kinds of firearm related accessories, just not the firearm itself or ammunition, presumably because they're not actually a FFL and can't handle the legal requirements.
My last employer was just as happy to bid on jobs building grow ops as they were solar farms, all while maintaining the insurance mandated drug testing policy.
The market for legal marijuana projected to be $100B by 2030. If the banks want a piece of that pie, then they will change the rules and "fix" the problem.
This isn't some incidental detail - it's the entire reason why the banking and credit card industry doesn't want to interact with cannabis right now.
Guess who regulates the banking industry and has authority over interstate commerce? The federal government. This particular example has nothing to do with credit card companies making a statement against cannabis, and everything to do with them not wanting to break the law.