If someone comes in and says they have an allergy to something, all utensils used are either washed or new to be sure their order isn't contaminated. If someone says they don't want peanuts, they're not gonna get all new utensils. They use the same ones just minus the peanuts.
In places like this they keep spoons and spatulas in a water well with running water. That doesn't necessarily clean them of oils from peanuts. It's basically like rinsing it off. It's hard to clean peanut oils off which is why stuff that don't contain peanuts still have warnings on the package.
This explains what they probably use in a place like that
https://youtube.com/shorts/CDwj_iF8ZU0?feature=share