What you’ve noticed is not a mistake. This attack speed increase is very small, increasing by 0.02 units per second. So it will take about 10 minutes to reach 100% speed. However, during this time, at least 9-10 attacks will come. If you develop all the parameters to 100%, it will take a maximum of 50-60 minutes.
Also, try talking to the witch and the captured girl 2 in all scenarios. This is a small tip related to the concept of the next game.