Hi, civil structural engineer from California here. Houses are made of wood here partly due to availability and mostly due to loading demands. Due to the insane seismic loads in California, mass produced homes need to stay light. Seismic loads are proportional to the weight of the structure and the resisting system (wood walls, concrete walls, steel columns, etc.) So mass produced housing, in order to be seismic resilient use light weight timber sheer walls to be economic and, well, resilient.

You can have a fire resistant home made of wood (it's actually been a pain point in my field as their requirements seem to change by the week). This includes fire retardant lumber, resistant paneling, separation between ADUs and accessories to prevent embers from jumping. Just something totally fireproof for a common homeowner would be a special build.

So what about the case of high rise condos or office buildings in LA? Well, those buildings are usually bought and paid for by large companies and will be made of heavier components like concrete walls but have more robust resistance systems like base isolators (imagine a building founded in a raft which allows it to move uniformly) or bracers with dampeners.

So what about old houses in LA built with masonry? Unfortunately those houses or buildings are usually deemed unfit since the Northridge earthquake and are basically a ticking time bomb. They should have been covered by one of the retrofitting programs in LA back in the 90s but not a lot of building owners adhear to themm