Words are inadequate

If it's only one side, either you're pedalling very asymmetrically -- consciously pushing with the weak side helps with that -- or the saddle isn't on straight. (Or has some other issue, like a high side.)

Tyres can help a lot with weather; disc brakes work in the rain in a way caliper brakes may not. But, yeah. Cars will eventually hit you because they don't care. Still statistically much better than not exercising.