I find it funny OP used Nettie as an example for showing that failing has no interesting consequences. Failing in that instance leads to several interesting options and different outcomes. And failing a DC5 skillcheck happens in TTRPG too. This usually leads to laughing at the table, and the player coming up with how he/she failed spectacularly. Just do the same when you fail a skill check. I haven't noticed any glaring issues where you just fail without having the option to solve the situation in some other way.