Eh, 10 is average for an untrained commoner. As an untrained commoner myself, I don't know that I'd do all that well at hiding in the woods, carrying a traveler's pack and wearing paladin armor...

To keep it zoologically on theme: https://imgc.allpostersimages.com/img/posters/black-bear-hiding-in-forest_u-L-PZVM640.jpg?artPerspective=n

I think you are unknowingly agreeing. Having hiked with typical people most would not notice that bear until it moved, made a sound, or was pointed out by someone paying above average attention.

A typical person not looking for the paladin, yes, they wouldn't notice that person. (Passive perception.)

Guards who are actively looking for infiltrators? They might very well do that, especially if there are multiple guards. (Rolled perception checks.)

In my group often times I'll do a group stealth check most of the time but if someone gets detected it can quickly turn into a problem solving encounter

Basically there's going to be like 1 person who tries to run and alert others and they have a small window to incapacitate that person to maintain their stealth even if someone in the party failed their check

Last session the party snuck into a cultist encampment, the ranger blew their stealth check while the rest of the party made theirs. The passive perception of the cultists wasn't an issue for the most part until a cultist finally saw the ranger but before the cultist could say something the rogue made a stealth attack on the cultist so even though the ranger got a really low score he basically became a distraction for the other party members.

They got pretty deep into the encampment (and had a couple close calls) before the alarm ended up getting raised because of the bold ranger stepping into a tent failing to check inside.

Fun session overall, the ranger had a night where all of his combat rolls were gold but his skill checks were crap.

Literally had a moment that boiled down to:

DM: "The cultist sees you and asks, 'Who are you and what are you doing here?'"

Ranger: "I'm new to the order and I'm trying to find the boss to get some new robes."

DM: "Alright make a deception check."

Ranger: "Fuck it, nevermind I haven't made a skill check all night. I'll just stab him. Nat 20. Max damage."

Edit: This isn't to say that "x rounds until alarm is raised" isn't a fun tool to use sometimes. Basically it's a picking the right tool for the right time.

Why are the non-stealthy characters trying to follow in the first place? Just hide nearby and come to the sneaky chsracters' aid if they fuck up. Or do something to temporarily boost your ability to sneak, at least.

ten minutes later, with assistance

Oh, everyone died because the monster had tremor sense.

Was that paladin an Adeptus Custodes?