A level 5 rogue will quite probably have a thievery dc of 13, if they invest in it and max dex. The average lock has a dc of 25 and requires 4 successes. It takes a roll of 12 or better to have a single success, and will average about 9 rolls to rack up those 4 successes. With 9 rolls wherein you crit fail on a 2 or lower, the likelihood of breaking a pick is ~61%.
Should a level 5 rogue take a minute to open the average lock, and more likely than not break a pick in the process?
And let's look at a good Lock: DC 30, requiring 5 successes. The level 5 rogue will only succeed on a 17, meaning it will take on average 20 attempts to get those 5 successes. On one attempt in a thousand our Lvl 5 rogue will open this lock before breaking a pick, and will typically break 3 in the process.
Am I missing something?
Seems excessive and boring to be honest.
IRL a person can learn to pick locks fairly easily, and with rakes, bump keys and combs makes it trivial.
I think DC13 for average locks, and DC18 for exquisite ordinary locks is fair. Trained skill only. Assuming done without time constraints or distractions.
If you're trying to do it quick or while being shot at you should absolutely expect DC25 etc..
Naturally anything that's really worth locking up tight will have secondary puzzle or magical countermeasures too.