Mecanum vs. Swerve Drive

[Nemo]

Why is it necessary to do fancy stuff (turning while traveling in a straight diagonal line, etc) in order to have a "good" mecanum drive? The best year for mecanum was 2011. All a mecanum drive needed to do that year was drive >90% of the time as a tank drive and strafe occasionally if that made it easier to line up to hang a tube.

Our team used a gyro in a proportional control loop to maintain the robot's orientation while it wasn't turning. I concede that I wouldn't want us to run a mecanum drive without that piece of instrumentation, because without it the robot's orientation drifts too much. Regardless, that's still not very difficult to pull off. It's a ways short of PID loops on every motor and field centric control, and it's much simpler than programming a swerve drive.