I don't have a problem with some locks being too complex to attempt but I think it needs to be a much wider range. I'd have something where if a lock level is 50 points below your skill level you open it automatically and if a lock level is 50 points above your skill level you can't attempt it. This means that even someone entirely unskilled with lockpicking would be able to access most locks while a newbie thief would probably be able to start with the ability to access all be the hardest of locks (and quite possibly any locks even at level one).
This makes sure that character skill level is important and you can't get by purely through player skill but also doesn't limit you much. Hopefully the system itself also makes character skill meaningful. In most RPGs I lean towards characters with lockpicking ability but in Oblivion security was a useless skill - and I absolutely hated the lockpicking minigame. I generally ignored lockpicking until I could get the skeleton key and then I'd just spam the auto-unlock. Oblivion's lockpicking minigame was the target of a lot of complaints and I imagine the devs gave this a lot of thought for Skyrim.
You've probably tried OOO already.
However that mod made picking locks a meaningful challenge, though TBH I disliked the overpowered effects of it.
As luck played too much a factor for my tastes not the actual lockpick skill.
Reason i bring it up is that player spells and or traps are mentioned as being in.
So security may actually apply to more than basic lockpicking.
All speculation of course but it would be fun if combined to an overhaul of picking locks from Oblivions metheod.