I disagree as a proficient skater. I can do various street style tricks and play roller soccer as well as dance. Their innovation is the stacked wheels to mimic the contact patch of a much larger wheel. They give you similar ability to traverse road imperfections as a tracked vehicle. I have fallen victim to small rocks despite being an expert skater.

The muscles you engage and the effort required in skating are entirely different.

A skateboard works great too for moving faster around town, and is pretty fun to use as well.