Now had it been some proprietary thing you can't verify, that could have been the case. But Bitcoin is 100% open source, you can review the code for yourself and verify that it works just as those who actually verified the code says it works. No need for blind trust.

Bitcoin is also not the first digital currency to compete with the big banks, it's the first you heard of because it survived. And it survived, because:

• It's open source, hence anyone can download and compile a node
• It's decentralized, over 11 000 nodes and as long as at least a few of them are up the network will be operational. Taking it out would be the worlds most complex game of whack a mole.
• It was launched underground and very discretely
• No known face behind it. That way big banks couldn't stop it by simply killing the creator and the few original nodes, which is how they eliminated every previous attempt before Bitcoin.

The ignorance is a shame, you overestimate the banks and underestimate the people. It's not a established fact that bankers will successfully kill and eliminate all competition, they will try and go to extreme lengths, but they will not always succeed. If you understand how Bitcoin works, it's pretty easy to see why they can't stop it by their usual methods.