Pre-9/11 there were a lot more.
HP as around 15 daily on a mix of 737s, A319/320, and 757... no RJs
I don't know how many Southwest had... a few more than today I'd suspect.
UA Shuttle was 7x daily with the 737s
American was running 5 or 6 daily with ex-Reno Air MDs.
I would suspect there was far too much capacity on that market. If you counted all 5 LA area airports you probably had nearly 100 flights a day on full-sized aircraft.
Stop drop and roll will not save you in hell. --- seen on a church marque in rural Virginia