Bibs have always been widely used by parents to make sure their little kiddo won't be making a mess everywhere, but such a thing aren't restricted to just kids. disposable adult bibs have been a useful, easy way of helping adults in elderly homes and hospitals whom for one reason or another cannot eat and drink without spilling. It's completely natural of course and generally no fault of the person in question, things like Parkinson exist after all that makes the motor function of the human body and its muscles do not respond currently to the will of the person in question. So, to help avoid spillage and a mess, you simply use a bib. But disposable adult bibs can often be used by dentists and doctors while they're doing an examination, simply so that the excess saliva and other bodily fluids may not make a mess everywhere.
Naturally, the frequent use of said bibs means that you can't just use a regular one that needs washing, as that would mean an excessive amount of extra cloth needing to be cleaned every day, if not hourly. So, with disposable adult bibs, you avoid the problem of needing anything washed and instead simply throw it away after you've used it and thus not needing to do any extra cleaning. Disposable health products in general are a common sight within hospitals for that very same reason, reducing the workload efficiently and not requiring clinics to hire in extra people just for the purpose of washing bibs and towels.