It comes down to how you ride. MY BLT is 24lbs on the nail, very light, all carbon parts. I’m happy to ride it seriously full tilt down Stannage/Long Causeway, but i ride very smooth.
Similarly my DH bike is a 36lb Demo 7, i run Mavic SX wheels on that, thye hold up for what i need, but i’ve been out with mates who on the same day as me have written of much heavier wheelsets due to the way they ride ‘at’ stuff, rather than ‘over’ it..