The Elite Fly MTB ones have a cover, separate from the drinking nozzle which looks big enough to keep dirt well away from the nozzle.
https://www.amazon.co.uk/ELITE-Fly-Water-Bottle-Grey/dp/B0BLZK5587
Those are the ones I am using at the moment, last well and easy to wash with no complex mechanism in the spout. I really can't see a reason for bottles not to have caps other than style over substance.
