To me an Adventure Bike describes a 50% street 50% two-track bike ridden with others who can help pick it up if needed. If you have friends who ride these bikes you might be more likely to ride to the bikes full potential. Not too many people want to drop a bike that could cost hundreds of dollars to repair or get their leg stuck under 500+ lbs of tech so they generally don’t stray too far from firm surfaces. They can serve as a great touring or two-up exploration bike and make the perfect justification to buy a super-cool helmet with a visor. The average rider goes to Starbucks to kick tires, meet with other ADV riders then group rides to lunch hitting some gravel roads on the way. Water crossings are the highlight of the day and supremely picture worthy.
Dual Sport bikes on the other hand are capable street bikes but comfortable in the dirt up to moderate singletrack. They can be dropped and picked up by the owner when riding alone. The average rider stops at Starbucks to take a piss if a McDonalds can’t be found. Packing a lunch that is still edible mid-day is of prime importance. Water crossing are also coveted photo ops with this group but your buddy stuck under his bike is the Holy Grail of digital capture.
Dirt bikes with lights are miserable on the street but capable of almost any dirt trails you will find. The average rider doesn’t know where a Starbucks is and grabs a cup of 7-11 coffee on the way to trucking their bikes to the trailhead. Beef jerky and a tug from the Camelbak is what’s for lunch. Pictures are few and far between because no one wants to ruin a camera or lug it around.
Suspension mods and aftermarket add-ons can blur the lines on the categories but ultimately it is who you ride with, how you ride, and your culinary expectations that should determine your purchase.