> because it doesn't work like this either in the car industry or in the bike industry
This is... not entirely true, there's heaps of standardized components in both industries. Think batteries, brake pads / brakes, springs, all the nuts and bolts, the OBD port, tires/wheels, airbags / seatbelts, and on the bike side, think cables, saddles (saddle pins), tires/wheels again, gears, pedals, etc etc.
While you probably can't fully repair one car with the other, there's plenty that has been standardized by the industry and legislation.