Earlier quoted context omitted.
If an ad blocker causes issues with banking sites then you either need a new blocker or a new bank
Bit of an unrealistic comment, this might be a choice you can make for yourself, but most people don't live alone and share their internet connection with others – I doubt telling your partner or housemates to get a new bank because of the DNS ad blocker you set up on the network will go down well. Ad blockers pretty much all rely on community-maintained block-lists, there are always going to be mistakes in those tha…
For other sites agreed, but a bank that can’t coexist with an adblocker you really have to ask yourself wtf said bank is doing.
Everything on that site should come from ad free reputable domains.
Also wouldn’t hurt if said bank tested their site with common browser configurations like ublock