Your Williamson County clicks and your City of Austin clicks are not the same product
An address inside the city carries a review process that an address in Williamson or Hays County generally does not, and the two produce different sales cycles, so they should not share a campaign.
A homeowner in Round Rock or Leander and a homeowner in Hyde Park may type identical searches, but the jobs behind those searches differ in schedule, in paperwork and in how long your money is at risk before revenue arrives. Averaging them into one campaign hides which half is working.
Split by county at minimum, and split the city out on its own. Set separate budgets, separate bids and separate landing pages. Write the ad copy for each so it names what the reader is actually facing, whether that is a suburban new build or a central lot with trees and a review step in front of it.
Target by presence, meaning people located in your areas, not people showing interest in them. Interest targeting buys clicks from someone in another state reading about Austin, and pool ads are expensive enough that the waste shows up fast.
Then exclude the places you will not drive on a Tuesday. A San Marcos job and a Georgetown job cannot both be convenient, and paying to find out is the most expensive form of route planning there is.