In VFX at the high-end (the smaller studios do often take shortcuts) we do model full layered materials with thickness, at least for mid to hero-level assets, so we would do the glass with proper volumetric thickness, with fully-correct inter-reflecting/refracting dielectric BSDFs modelling the glass, with correct IOR and total internal reflection.

It is slower to render than using "thin glass", and lighting the checkerboard surface underneath the glass isn't as efficient (you can't do naive Next Event Estimation through the refraction of the glass volume, but you can do manifold walks to solve that), but we do it at that level of fidelity often enough when required and have been for years. There are times when it's not required though, so approximations can be acceptable in more forgiving situations.