These are vanishingly small postage stamps compared the absolutely vast sprawl that is LA. I mean seriously. Get on the 10 and head east. Let me know when you get outside the sprawl. It'll be over an hour at highway speeds. It's that big. Just the city of LA itself is 503 square miles. Santa Monica is (nominally) 8 square miles--and most of that is not what you are referring to. 3rd street promenade, a few beachfront streets, a few blocks on Wilshire and Santa Monica blvd. I have a feeling you never really drove around LA and appreciated how absolutely massive it is.

And here's a nice infographic comparing the density of LA and New York, if you're interested in more than anecdotes:

https://www.its.ucla.edu/wp-content/uploads/sites/2/2014/05/...

TLDR; no, LA is not mostly dense, walkable areas. Very far from it.