What makes someone stick to Delta over United? And vice versa.. Currently faced with the decision of one or the other. I'm OK with living in any base wishing for Houston-United or ATL-Delta.

I've read in threads a lot say to choose United because Delta has hired so many pilots in 2015 (pre pandemic) and WB captain (A3330/350)would take so long but at the same time so many choose Delta this 2021/2022 I'm wondering how come?