Our laser, and others that are similar all have air assist built in. It’s absolutely necessary to keep the dirt off of the lens. The amount of air that goes through isn’t that much in volume so it’s not blasting smells/smoke all over the place.
I think it really depends on what you’re cutting… I’m always careful to look up what materials I’m cutting ahead of time to make sure that the fumes aren’t harmful.
For me most of the time I am engraving/marking wood. Using either the downdraft table I made: Vacuum honeycomb table for laser cutting - #6 by jjneeb
Or the 3D printed shoe to pull the air away. Either method works really well.
When I’m marking metal I don’t need any extraction.
I don’t use the laser all day every day and I find these methods (and materials) more than sufficient.
If you’re doing material that is more harmful, or in more volume it might be worth looking into other methods of extraction.