Every year, billions of vehicles worldwide shed an estimated 6 million tons of tire fragments. These tiny flakes of plastic, generated by the wear and tear of normal driving, eventually accumulate in the soil, in rivers and lakes, and even in our food. Researchers in South China recently found tire-derived chemicals in most human urine samples.
I guarantee your '98 BMW is still way faster than my '90 Miata, and even that is still a sports car that still deserves and requires decent tires. Therefore, yours still does too.
I wasn’t being hyperbolic when I used 49cc scooters as an example – I really do think that’s pretty close to the limit of how much power a motorcycle can have and still reasonably use long-wearing, not-very-grippy tires.