3D printers, do you use glue stick?

I have found myself confused about glue stick on the heat bed. I always have some applied, either reusing some from a previous print or applying it fresh. I manage a small print shop and have seen many prints fail, even on nice textured PEI plates, because no glue was used. I’ve seen prints fail only where there was no glue under the part many times. Yet I frequently hear from people, face to face, that they never glue. I’ve seen these people’s prints fail because they don’t use glue.

There are even special plates you can buy (SuperTack plates) that stick extra well to PLA to absolve you of the need for glue. But I find these coating on these plates to be too fragile.

Overall it seems like there’s a large contingency of people risking their prints and purchasing accessories to save what is maybe 20 seconds per print (that’s including periodic cleaning as you can reuse the glue many times). How do Tildes people feel about this? I teach a 3D printing class and tell people to always glue as they have nothing to lose. But maybe I’m missing something.