If an ad blocker causes issues with banking sites then you either need a new blocker or a new bank
Ad blockers pretty much all rely on community-maintained block-lists, there are always going to be mistakes in those that break some sites, or some sites might not act well when unable to send ad/tracking events. I recently had an issue booking a train, which was because of this, turned off the ad blocker and it worked fine, not something that's as easy to do with network level blocking, especially if it was set up by someone else and you're not a technical person. Not booking the train because their site is bad is not a realistic option.
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
If you value your finances at all, you won't allow advertisers into the connection.
* Bug, or feature, many fail if the tracking is blocked, due to other code that assumes it's there or depends on it. They fail closed instead of fail open.
Banks and other financial institutions have a duty to prevent fraud and their malicious actors. Could they do better, yes. They still have a duty nonetheless.
Adblockers do more than just domain blocking, such as anti-fingerprinting, bot detection—which includes a lot of, sadly, invasive checks against the browser.
UBlock has annoyance lists, tracking lists, and others and others…
From what you’re telling me, you’re wanting a bank that’s protecting their clients or at least attempting to. Ooookay