Other ad blockers block ads. When you go to your bank's website with other ad blockers you're pretty sure you're connected to your bank as the bank's certificate is trusted. This acts as a proxy and uses its trusted certificate to tell you that the bank's certificate is legit. The problem is that it doesn't actually care if the certificate is actually legit. If it's not your bank's website and is actually a clone made by some guy sitting in Lagos with a laptop that you're giving your bank credentials to, well the proxy is ok with that because it didn't check to see if Mr. Lagos' certificate was valid.