Maybe I don't get it, but that seems completely unsecure, isn't it? In fact I wasn't sure if this was some kind of parody, especially XORing strings and calling that "almost perfect encryption".
If you can generate a secure keystream (for instance, from pure random data well in advance of your message encryption), you can use just XOR and nothing else, and that system will be difficult to attack mathematically.
XOR as a concept gets an unjustified bad rap amongst generalist engineers because of all the terrible Rube Goldberg XOR schemes other developers have come up with. It's authentically essential to strong cryptography, but very easy to misuse in weak crypto.
If the key size is at least as large as the plaintext AND the key is truly random then it actually is a perfect encryption, because every single bit in the output is going to be random. It is called 'one time pad' -- https://en.wikipedia.org/wiki/One-time_pad
It's a real encryption, much-much better than basically anything before because it's really unbreakable.
For example, you generating a 1TB key before leaving on a trip you could imagine a VPN set up that encrypted 1TB of traffic in a way that was theoretically unbreakable by someone sniffing the traffic only.
It's not useful or practical in many situations that we associate with cryptography over the internet, but it certainly has its applications.
Almost every other cryptographic scheme exists in order to increase convenience, at the expense of some security. The one time pad method is "perfectly" secure (assuming the key is securely generated, and kept safe), everything else is less than perfect (although computationally improbable).