If you tap above a bar you can make them larger again. The bars are scaled to always stay relative to each other, the point is that you can explore back and forth to see the relative time it takes to complete various operations for a computer.
Why can I tap the largest bar so much that it can become as small as others in the end?
Why can't bars just auto-resize when I scroll the page horizontally?
You're the designer here, so it's up to you to shape user experience to deliver your point. Instead you allow users to ruin it for themselves and don't even try to control the narrative of the page. Sorry, don't know what you wanted to do here but I don't think it's working.