The loudest ones?

The 51% that voted for them out of the 20% of total voters?

I mean, this does get very hard to define.

Then what is the point of even having them and not just voting for everything directly?

There are a variety of differences between having representatives vote with your interests and voting yourself, such as practicality, time expenditure and access to advising and expertise, etc. That’s perhaps why many direct democracy systems (California, Switzerland, etc.) combine the two with direct democracy used for relatively few decisions.