It's not. Source: I actually own it rather than having to rely on making broad generalisations.

> I live in a city

I also live in a city, many of us do. You are not unique. Many of us in my street have had to file numerous noise complaints against various cars in the street, yet i've never received a single complaint about my bike.

> I see that 99% of bikes are fucking twice louder as any car

Sounds like an issue specific to were you live. I couldnt tell you the last time I heard a bike around here, but the peace is disturbed here by a car almost every other minute of the day.

In fact, we have to pack up and move house because our neighbours car and his friends cars are so absurdly loud and they will sit there and just rev the shit out of them for 20-30 minutes at a time multiple times a day.