If we remove auto fail on 1 for stealth check we still will fail, when rolling 1 in most cases.
Would we?
I mean, last time i was paying atention to skillchecks, it was with Astarion and i had 12-15 bonus!
Would love to see sources of those bonuses. There could be messed up numbers pretty easily or you're not saying that it was with advantage or Shadowheart's buff, which is godly powers and failing because of some stupid 1 with them sounds even more stupid.
And no one says here that steath should be undetectable by any means.
And what else is inability to fail while rolling 1 if not this?
There is no such thing as inability to fail stealth check while rolling 1 in normal circumstances. And I explained why already. Rolling 1 makes us fail even at easy tasks that has 5DC for the rest on this levels they are just making us fail more often. Stealth check normally has at least 10DC.
Anyway. My last answer to you on this topic. You can go read the book and do some math yourself.