I think Big Lots has about 10% of its stores in CA likely leftovers from MacFrugal/Pic N Save.
Are the stores you see closing former M/P stores or are they stores Big Lots later opened?
To be fair I have found the stores Big Lots opened on their own, are quite a bit nicer than the M/P Stores.
I was recently in a Big Lots in Placerville, CA which the company remodeled. It looked pretty good (given my expectations when entering Big Lots are very low, like, underground low), but not very busy. I do find it odd consumables/food were in the back of the store.
I see the Big Lots in San Francisco closed back in August. I am a little surprised there was a Big Lots there in the first place.