As a matter of course I avoid United, and American doesn't have much presence out of SFO or OAK. Delta has done right by me each and every time something's come up.
Stuck on the tarmac in the snow and miss the connecting flight (last of the day)? They automatically rebooked me on another airline and I got a notification from the app as soon as I had reception.
3+ SFO bound flights delayed at JFK because of crazy winds at SFO? They proactively encouraged people to rebook, gratis. I rebooked on a flight the next day on nicer equipment, through the app, went into town, grabbed some bagels and had a flight at a nearly ideal time of day.
Regional plane goes tech? They had a red coat out and about keeping everyone informed.
Missed a flight because I misread the departure time? They sold me a same day ticket on the next flight at a hefty discount and I kept the inbound leg.
Southwest has a huge disadvantage and it's not tech: it's the lack of interline agreements. Nearly every other airline (except perhaps Spirit) can rebook you on another carrier when things go sideways. Southwest simply can't. With an interline agreement in place you'd have far fewer people getting stuck with exorbitant last minute fares.
In general though don't fly when you're getting unusual weather. Less than an inch of snow at PDX throws everything into chaos (and Portlanders call it fucking snowpocalypse). A few inches of snow at PWM and they don't even blink.
Notably, per the Alaska agent I spoke to about my cancelled Alaska flight, Delta doesn't let other airlines rebook on Delta flights. That may just be an Alaska/Delta thing but it's not obvious full reciprocity.
I find it hard to believe that Delta (or any other major airline) wouldn't reciprocate. When I got rebooked onto an Alaska flight, the gate agents were openly annoyed at having to accommodate Delta passengers. However, the relationship between Alaska and Delta has grown more adversarial so who knows.
I should also add that a few years back when my Southwest flight out of SFO got cancelled I was able to book a seat on a flight out of OAK with a minimum of effort. I think I had to pay the difference in fare though. When it works, it works, but the go it alone attitude will only take you so far.
Stuck on the tarmac in the snow and miss the connecting flight (last of the day)? They automatically rebooked me on another airline and I got a notification from the app as soon as I had reception.
3+ SFO bound flights delayed at JFK because of crazy winds at SFO? They proactively encouraged people to rebook, gratis. I rebooked on a flight the next day on nicer equipment, through the app, went into town, grabbed some bagels and had a flight at a nearly ideal time of day.
Regional plane goes tech? They had a red coat out and about keeping everyone informed.
Missed a flight because I misread the departure time? They sold me a same day ticket on the next flight at a hefty discount and I kept the inbound leg.
Southwest has a huge disadvantage and it's not tech: it's the lack of interline agreements. Nearly every other airline (except perhaps Spirit) can rebook you on another carrier when things go sideways. Southwest simply can't. With an interline agreement in place you'd have far fewer people getting stuck with exorbitant last minute fares.
In general though don't fly when you're getting unusual weather. Less than an inch of snow at PDX throws everything into chaos (and Portlanders call it fucking snowpocalypse). A few inches of snow at PWM and they don't even blink.