It's not that I want to take anything away from the Rogue, but I'd prefer flatter numbers in the system that was supposed to care about flattening numbers and not pushing modifiers off the d20*, so I'm not stuck trying to figure out if a guy with a check of +5 is a village idiot compared to a guy with a check of +17 and beyond.
If all bets are truly off, and numberflation is just as real as it ever was, then have rules for epic skill check results for these phenoms who can routinely hit so-called "impossible" DC's.
That was what broke the 3e skill system. Numberflation.
At the end of 3e revelation came to me that you should not use class skill cap as guideline, but instead use 10, 15, 20 and 25 and be happy with that.
If you consider cross class skill cap (3+level)/2 as standard bonus, you are in the range of +2 to +11. With ability scores ranging from -1 to +5 on average it plays quite nicely with those ranges.
And characters that have those skills as class skills will eventually get to the point where they won't fail at all at level 15+.
And then you could use take 10 if the stakes are low or take 20 if there is plenty time.
So I consider this a good progression for proficient and expert people.
In 5e, without any special ability we are at about half that number. Or better: we start with the same bonus and the progression is only 40% of what we got before. So special abilities need to cover for what I considered a good progression. This is where reliable talent kicks in.
A rogue at level 20 has a floor of 22, without considering their stat bonuses. So they need 16 in a relevant stat or some extra bonus to make 25 DCs reliably. A fighter that somehow gets expertise has floor of 14, but their average is 28 using with second wind. So without good stats they are even more likely to make 25 DC checks than the rogue.
Or hey, maybe we could just get rid of skills, go back to OD&D where the DM can decide if a character can do something with an ability check, and give the Rogue back their bespoke "super skills" (ie, Thieving abilities).
They have super skills. Reliable talent allows them to do things most other people can't do reliably.
And given their high bonus, they eventually make DC25 or DC30 checks that allow them near impossoble results.
*At least, I think that's something someone at WotC claimed at some point. Maybe they never did and I just assumed that's what the point of this all was.
+17 is within the d20 range...