tubeless for gravel. Before I switched, I would get tons of flats. With tubeless, none. I do lose pressure between rides; my last rear tire probably had 20-30 spots were sealant would leak a little. But they hold pressure during the ride, which is all they need to do.
Even though I'm tubeless, I still carry a tube as sometimes even sealant isn't enough. Two tubes and a patch kit if going into very remote areas where self-rescue is critical.