Which steps in the conversion funnel are the most difficult? Why-Which step is the most important? Why?

Digital marketing

Read the case study attached, and answer the following 3 questions. This is not an essay, Don’t need an intro, just list the 3 questions below and answer them. One paragraph each.

Map out Drop’s user acquisition funnel.
Which steps in the conversion funnel are the most difficult? Why?
Which step is the most important? Why?