Again - it totally depends on your travel (if any). There is no one size fits all. I’m at a United hub and the United card offers great discounts on award miles - we saved 75,000 miles per person on business class tix to Japan (x6) the card more than paid for itself even if we never checked bags or used the lounge. My son checked 8 bags when he moved out (I get 3 bags per person). Again paid for the card for at least a few years.
But it doesn’t work if you’re in an American or Delta hub or if you want to deal with Southwest (never fly). I fly 7-10x a year so it’s not hard to figure out what makes sense for us - infrequent fliers need to figure out if an airline card even makes sense at all or their better off with a card that transfers to a bunch of different airlines.