I don’t love any airline’s rewards program at the moment but I choose DL and stick with them because a) they seem to be the best of the big 3 domestic airlines b) flying without status sucks and c) I want to be able to utilize my AMEX platinum skyclub perks (which can only be used if you’re flying Delta).
Like any consumer, I wish businesses were more generous in how they reward loyalty but the reality is they have to make their money and can’t give people free or discounted products left and right.
You are, however, spot on in your complaint about the lounge access.