This. Over half of my flights in domestic First Class in the past 4 months have featured at least one or all of the following:

-flight attendants who didn't bother to do more than one or at most two service/drink passes during a transcontinental flight, and then got visibly annoyed when summoned from their group gossip session for a refill
-borderline inedible "food" that looks like something frightening I once encountered in Alitalia coach
-running out of the only 2 recognizable meal options halfway through First (leaving some sort of unidentifiable vegan/veggie mush as my only choice)
-rude, indifferent, or dismissive flight attendants
-20+ min waits after gate arrival to find a ramp employee to connect the jet bridge
- internet that didn't work
- broken/inop video screen

My favorite...... on my last flight there was a young FA with a huge chip on her shoulder. I merely asked her politely for a bag of chips on a transcontinental flight after no one came around for nearly 2 hours. She said to me "we're not doing that right now!" in a nasty tone of voice. I was sort of shocked but just let it go. The other older FA must have overheard this as she came by a minute later with two bags of chips, winked at me and rolled her eyes in the direction of the "No chips for you!" FA LOL. Not long after the same nasty FA got into an argument with another passenger who complained about the lack of service. She spent over 5 minutes arguing with him, instead of using that time and energy to just bring bring us our damn snacks!

I don't know what is going on but Delta service quality has declined noticeably post COVID.

Other than International where there are far better options in terms of service, I've been a loyal Delta customer and pretty much only fly Delta domestically unless they don't go where I need to go. So I have no idea how much worse the other domestic carriers may be.....but I'm about to find out as it seems Delta just fired me as a customer.