It’s sort of hard to put a pin in it, but, I would say my recent DL experiences have been mostly meh.
Many cabin crews are great, some are clearly phoning it in.
Most cabins are clean, some are not.
Reliability of the operation is much worse than the glory days of “the on-time machine”. Now its just meh, we’re usually on-time but 🤷♂️
Airport experience ranges from meh to good, never great.
Point is, it’s become closer to every other airline. Which means the price premium is absolutely not justified.