Maybe someone else can give you a more accurate answer. I also live in SoCal but near San Diego, very HCOLA. I was ball-parked ( a few years ago) $100 linear foot for a slumpstone wall, with stucco to match the house. It wasn't a formal quote though, and I didn't get bids.

Fencing is less expensive, and where I live, many weekly landscapers can do that job. You can also sign up for the Nextdoor website where you live and do a search in the comments for "fencing" or "fence" and you will find recommendations for local fencing contractors.

The view of the fence would be much more attractive, if you had the gardening bed run all along the fence and could plant something to cover it up.... like (my recent favorite) Italian cypress. And I see a few in the background there.... and find a new home for the pool net.

You need to find landscape that doesn't drop a lot of stuff in the pool.

If it’s not rotting just paint it till construction and materials prices are back to normal. Things very pricy this year.

Considered vinyl privacy panels Im in Pittsburgh though so $100 is about ten here.. but it’s a permanent solution and in my opinion more attractive than a block wall. Much much less foundation work required.

https://fencefactory.com/vinyl/