Look at the bars carefully
Those bars are not counting keys. They are counting digits. If they counted keys, the first five would all be invisible specks and the last would be wider than the solar system.
Every extra letter of key does not add to the pile. It multiplies it. That is why a four letter key falls instantly and an eight letter key takes minutes: four more letters made it four hundred thousand times harder.
Modern encryption is nothing but this idea taken seriously. Nobody has ever found a clever way through AES. They do not need to be clever, and neither does the cipher: the pile of keys is simply too big to walk through, and always will be.
But a big keyspace is not safety
A scrambled alphabet has four hundred million million million million keys and a nine year old can break it in ten minutes by counting letters. The keys were never the problem: the cipher let a pattern through.
So a cipher needs both. Too many keys to try, and no pattern to follow. Miss either one and it falls.
And even with both, the humans go wrong. The one-time pad cannot be broken at all, and it broke anyway, because somebody printed the same page twice.
The one-time pad Frequency analysis Brute forceRead more elsewhere
Longer, harder and written for grown-ups. Worth a look when this page runs out.