These rates are generally dictated by the card companies. We recently had a spike in chargebacks in one of our Stripe accounts, which put us over the warning threshold.

Stripe could have handled it a lot better. They withheld payments from us (over 250k) No notifications, or anything else. They waited until we contacted their support on why our payouts weren't processing before they lectured us on how we should be doing fraud review (we do. We also pay way to much to SiftScience to mitigate that as well)

tl;dr though, Visa, Mastercard, Amex, Discover, etc... all have their own hard limits.