I think it depends on what you consider a professional job. There are professional repainters who use airless or air assisted airless and water borne paints, especially for repaints of cabinets already in kitchens.

You can get outrageous glossy finishes with a brush on furniture if you know what you’re doing and use the right product.

There’s learning curves and techniques to pick up for different paints and materials— what I’m trying to say is you need to figure out what kind of paint you plan on using, which is a question of how much space you’re willing to devote to painting and drying, whether you’re going to construct a paint booth— stuff like that.

This isn’t a “there’s a right answer, and a bunch of half-measures” kind of situation where all pros do one thing all the time, and everything else is for idiots.