iserith
Magic Wordsmith
I play a paladin with a mount and it hardly ever matters. Mounts are too squishy. Sometimes I’ll use it in combat and let it attack but only in an emergency because I don’t like when it dies because I don’t have the slot to recast it and it’s usually carrying most of my gear. (And sometimes the group’s loot). Now all my equipment and saddle are on the ground (or in the water in your example). Saddles are inconvenient to haul around.
A player in this West Marches style campaign I'm in is on like his seventh war elephant. He just keeps recycling the barding. I even took one of his elephants out once with a random encounter of griffons when I was DMing a game.