The number of transactions per block in bitcoin is limited. As bitcoin became more popular, the number of transactions grew in the past years and created the problem that transactions took longer as the Bitcoin blocks were full. So you had two choices – either wait longer for your transaction to be processed – or pay a higher fee to get it processed faster.
We agree that this is an unpleasant situation which needs to be solved but on the other hand it was also artificially created by Spam transactions on the Bitcoin blockchain to create that exact problem.