Yeah I just tried to batch delete from my steam folder outside the game, but they're being saved in the cloud I guess. So the only way to get rid of them is to manually delete the saves 1 by 1.
I'm the kind of player that tends to wipe saves periodically as a way of trying to get invested in a new character in a second or third playthrough. But I think that'd probably take like 20 minutes in the carpal tunnel to do right now, so I just have a ton. Creating a new session seems to be the most convenient way to blank slate it, or to organize saves in a more sensible way by character. But I'd rather I could just nix saves more easily from the main menu.
I also wish I could name/rename the save, since right now all you have to go on is the screenshot and the area/time description. Just feels kinda clunk for something we interact with pretty constantly with each load.