Oh yes. There are SO MANY instances of "DC 15" (usually) that make little or zero sense, and would make all the sense if that DC was "typical" or "default" or something.
- Identify any ongoing spell: Arcana DC 15
- Climb any tricky surface (slippery or with few handholds): Athletics DC 15
- Avoid full damage falling into water from any height: Athletics or Acrobatics DC 15
- Swim in all kinds of rough water: Athletics DC 15
- Everything tool related: detect any poison with a Poisoner's Kit, spot anyone cheating with a Gaming Set (DC 10), identify any substance with Alchemist's Supplies, detect any poison in a drink with Brewer's Supplies or in food with Cook's Utensils, appraise any gem with Jeweler's Tools, disarm any trap (well. on paper.) with Thieves' Tools (DC 15), pry open any door with Carpenter's Tools [whereas forcing a door open without tools has a scaling DC from 10 to 30 per the DMG], win any game with a Gaming Set, duplicate any wax seal with a Forgery Kit (DC 20)
- (with the exception of a tool use that seems to say that, but is specified elsewhere to say something else: lockpicking is not a flat DC, it depends on the lock)
- And of course the inexplicable Stealth DC 15
And RAI is opaque here. I have no way of knowing which of these flat DCs were meant to be default but there was shoddy writing involved (like locks), and which are a deliberate choice of game design. The Influence action does say "default" DC 15, so they are clearly aware this is a word!
The good news is that the DM can easily adapt all of that, so on some level I do realise I'm whining for the heck of it. Please forgive my grumpiness.