For me, it depends on the bow, my personal hunting bow I like to have a new bow with a warranty. My wife and kids hunting bows I can get them cheap enough that it doesn't make sense to take the loss on a new bow, they also don't hunt as I do. I spend a lot of time archery hunting, I probably average 50 days a year dragging my bow around and abusing it in the elements, and want it to last.
I've had 4 sets of limbs replaced due to splintering and one riser replaced all under warranty bows from two different companies, those items alone made up the difference in buying new vs used. I also shot my last bow for 8 seasons which is also a factor for me. I wouldn't be afraid of a used bow and all of the bows I've sold to people have been well taken care of and dialed in for them when they got them.
Sometimes you just get a lemon bow as well, I believe the majority by far are great bows. My buddy bought a New old stock RX1 a couple of years back and the first time he drew it back the roller guard pulled out of the riser. He ended up taking it to a local Hoyt shop and the shop epoxied it in at the recommendation of Hoyt, the seller worked with that shop to make it right for him, and ever since it's been a great bow for him.