Yes, live plants transpire yielding higher humidity. Fake ones do not but will not lower humidity either. Try both & see what you prefer. Fake are easier to clean, don't usually get eaten and 'live' a lot longer. Live plants can provide a, usually short term, food source, grow naturally but may need maintenance and help balance the microecosystem created within an enclosure.
Thanks. I might take you up on trying both instead of one or the other,