They all use wood, think a lot of them are wooden cues made by John Parris, but he has something ridiculous like a 10 year waiting list if you want to buy one of his cues. Snooker has been very traditional, but there has been a recent trend of players moving to titanium ferule to reduce deflection instead of brass which was the norm before (before that never really heard snooker players talk about anything equipment related to reduce deflection).
There was an interesting episode of Karl Boyes Youtube channel where he had Gary Wilson (pro snooker player who also plays some pool tournaments) talking about his pool cue and they ended up getting into a lot of detail about how the ferule material effects deflection, but also about how wood and carbon deflect differently. He mentioned something I hadn't heard before, the harder he hits a shot with a wood cue the more deflection he has, whilst with a carbon cue the harder he hits it the less deflection you get. Don't actually have experience of playing with a carbon cue to corroborate that myself, but found it interesting. He sees snooker as his main career so he doesn't want to get used to something to different from his snooker cue at pool, but said if pool was his main priority he'd play with carbon as he feels disadvantaged at playing power shots using a wooden cue.