Answer:
Vice Presidents have a lot of duties to help assist the Presdient. VP's do things such as breaking tie votes in the senate, traveling abroad when the President is not in a fit state, taking the place of the President if they were to ever pass away or fall ill and they act as loyalists to the president, meaning that their opinion on a subject is always taken very carefully when the president is in need of answers. I'd say their pretty important as they act as a backup for the president.
Random fact I didnt know: almost one-third of VP become president at some point