Laser cutting brownies is probably fine. That said, there's plenty of evidence that fumes from cooking can negatively affect indoor air quality. You should always open a window when you cook.
So yeah, there is probably lot going on. From simple water vapor to those by products that come with browning.
I don't think it's a recent issue. It's law, where I live, to have ventilation to outdoors, at any source of combustion gasses. Most of the "recent" papers say that most of the problems can be removed by using that fan that's right above the oven, by law. I am surprised that it's not also law to have these fans turn on automatically.