I'm not underestimating the technology used in the M5. If anything, though, the M5's technology is the one that I would describe as "incremental." They took an internal combustion engine, the mechanics of which have been well-understood for over a century now, and improved it incrementally until it became a twin-turbo V8 that has a ton of horsepower.
Contrast that to the Tesla, which has been engineered from the ground up to use batteries to power it. The car is a technological marvel, even compared to cars like the M5. And this translates to a driving experience that is different enough from ICE cars* that it makes it a disruptive tech.
*instant acceleration, no engine noise, real-time graphical feedback about the car's systems, etc.
Contrast that to the Tesla, which has been engineered from the ground up to use batteries to power it. The car is a technological marvel, even compared to cars like the M5. And this translates to a driving experience that is different enough from ICE cars* that it makes it a disruptive tech.
*instant acceleration, no engine noise, real-time graphical feedback about the car's systems, etc.