The only DC you can fail that lead to combat are DCs you take to avoid combat or take to ask people to do something that should piss them off. The combat on failure is the expect result.
For the others, depends what the situation is. The "fun" was mostly to say that failures didn't lead to nothing happening or game over. It wasn't about the failures looking like another color of success.
Here's my point. Most of these dialogue choices are flavor only. Some might lead you to getting some minor reward if you succeed and some may lead to unprepared combat if you fail but so what? If you're playing table top D&D and your DM tells you to roll for something and says you failed, do you make them let you have a re-do 23 times? No, nobody would do that so why do you want/expect to do it in this game?
People are used to play interactive movies adventure games labelled as RPGs where each dialogue options is a deterministic option and chance isn't a factor. "You want to avoid combat, press A. You want to do combat, press B." They think role-playing is building a narrative based on outcomes and they want to make that "perfect" playthrougth.
BG3 doesn't allow them to do that unless they cheat or savecums the DCs.
