[Abra Cadabra IV]

Tank is probably the easiest, fastest to build, and (if you use the kit parts) cheapest drive train available, so naturally it's going to see a lot of use by new or poor teams. Other drives that work better just take too long, are too complex, or are too expensive for many teams to build. My team is currently going through a money/mentor crunch, so we're going with tank drive (even though we really wish we could build something else).