That was exactly the situation. I did it on purpose as a test. The one character that was up could not possibly win so I, effectively, engaged in a stalemate. I don't have a problem with it but I thought it was interesting that I could just keep helping the downed character up. I thought there would be a limit; which would add to the game's difficulty.
Makes sense. This could also be solved by AI changes, where the AI begins to target a character that keeps reviving downed allies. This would shake things up a bit, but honestly would still result in combats being ~unloseable if you have more PCs than enemies.
Replacing BG3's Help Action with 5e's Help action - or making it so the Help action only stabilizes, doesn't bring to 1 hp - would be better. This would force you to use consumable resources (potions, scrolls, or spell slots) to revive downed characters.
Other solutions could be giving characters mechanical penalties every time they're brought back to 1 hp in a single combat or, when characters go to 0 hp, they start with 1 automatic failed Death Saving Throw per every time they've gone down previously in the same combat. But these solutions are adding homebrew on top of homebrew, which isn't the best.
