There's the other end of the scale where players feel that their character is so insulated from risk while scouting that they want to do things like scout the entire "dungeon" while the rest of the party hangs back waiting to be called in.I'm just saying that if you make scouting significantly dangerous, then you shouldn't be surprised no one wants to do it. I mean, why would they? If they wanted to take danger all by themself, why be with a group in the first place?
Lets say Alice gores off to scout leaving Bob Cindy Dave & Edith behind. Without attrition there's no real risk of being split up unless monsters are able to basically execute Alice or trap & kill her almost immediately unless the gm steps in to kill her by saying "no guys you don't know she's in danger" to be rushing to her help, It doesn't really matter if Bob Cindy Dave & Edith get attacked while Alice is away because anything that could meaningfully impact the 4 left behind probably won't be impacted much by a 5th. With attrition Alice might get smacked a couple times rushing back to the group but those smacks add up & eat into the party's resources.