It's a reasonable question, and it's one of the things about airline status that I actually value a lot, so here's an attempt to answer it. First, if you have

It's a reasonable question, and it's one of the things about airline status that I actually value a lot, so here's an attempt to answer it. First, if you have carry-on luggage and the flight is full, this guarantees you access to overhead space. That can be a big deal. Having to gate-check your bag can be irritating if you've got things in there that you need, and the longer the flight, the more important this is. Second, at least on Delta, the people who board priority have a separate line. That line continues to exist even after general boarding starts. The upshot is that, even if you board with everyone else, you can cut the line and not have to stand around waiting. If you prefer sitting down to standing in a line, then this is valuable and good. Third, and related to #2, boarding early means you're likely boarding with other frequent travelers. Those people are better to board with because they are quicker and more efficient, on average, about things like clearing out of the aisle, getting settled, etc. This means less waiting around and being jostled in the aisle. All of this adds up to a much more pleasant experience.