Poway calls itself the City in the Country, and a lot of homes here, from Green Valley to Garden Road, sit on bigger lots than you find closer to the coast. A bigger lot usually means a longer line from the house out to the street, and some properties run to a septic tank instead of the city sewer. A longer line gives a clog more places to sit. A short hand snake from the sink won't reach most of them, and a clog it can't reach doesn't get cleared.
So before anyone heads out, you tell us what's going on. Which drains are slow, how long it's been happening, and whether the house is on sewer or septic. Those answers help decide what equipment comes out, from a cable machine for a simple clog to a camera that can show how far out the problem is.
If the pipe itself turns out to be the problem, you'll be told plainly, with the reasons laid out. If it just needed clearing, you'll hear that too. Then it's your call.