The threat model where the analytics company is hacked. I don't know why you would trust your bank to never let that happen.
There are some APIs on the bank site you need to conduct your business, and there are also some extraneous APIs. Yeah, sure, you tell the bank it's their fault clickwatcher.js got hacked, and maybe they give you your money back, but it seems like unnecessary exposure to unnecessary hassle to leave all that crap running fully trusted.