They literally don't care. Don't tell them "the truth", don't tell them "what's wrong with the company", nothing. Just say you've enjoyed working there and if things turn around you'd be open to coming back.
The best outcome for an exit interview is you leave on good terms so you can use them in the future if necessary. You never know when you'll need a reference.
Again, any criticism or negativity you bring to the exit interview will just be used against you. You'll be labeled as disgruntled, or whiny, or just didn't have what it takes. And that will cut you off from using them in the future if you need to.
My partner got laid off in a beeeeg round of layoffs, worked with me at the same company. I wanted to be laid off SO BADLY so I could take some time off work to spend with them—we had the means to take some time off.
A month passes, and one day my boss calls me into a room where our HR person was sitting. They’re both suuuuuper morose, my boss looks like she’s about to tell me my gramma died.
I’m BEAMING. They pull out papers and start explaining, ask if I have any questions, and I’m like
“excellent! I gotta ask about severance” (yes absolutely)
“so I can do the whole unemployment thing? (yes you can)
“DOPE! Do I have to work the day out? (…uhhhh no, you can’t)
“Stellar! Mind if I go say goodbye to some people?” (Absolutely, take your time)
As I left the room, HR person was like “I must say, Rai, this is the most unconventional one we’ve done so far…” and I thanked them and frolicked out. Gave some hugs, got my stuff, and dipped.
That was December 2019. The timing could not have worked out more perfectly.
If you get laid off "ethically" (as in the company really does have budgeting issues and they really are trying to weather the storm and they really are cutting back your role which isn't critical to continued business operations) then there might be potential options to come back in the future if the business can course correct.
If you're getting laid off because they're too cowardly to fire you, yeah. There's no position to come back to.