Interesting experiences. Are you flying in F or E/E+? On LAX-SFO/SFO-LAX they do not cater snack boxes, I have asked many many times going as far back as 2016. Was never able to get one then, don't expect to be able to get one now (I haven't asked in the past year though).
My experiences this month:
LAX - SFO / SFO - LAX in F; Snack basket & drinks (water, etc)
ORD - YYZ in F; Snack basket & drinks (water, etc).
*Snack basket = normal assortment of cookies, bananas, chips, biscoti, etc.