The rest of your comment try to justify car usage by taking less than 5% of the transit in the city, when there is already exception or infrastructures made for the scenario you described (except elevators and accessibility, thats a big issur in paris intra-muros). Yes, there are a lot of people that use the car when they can not use it, thats still most of the car traffic.
so, do you have any data to back up that assertion? (I won't claim that I have any favorable to my argument, just the observation that driving in and Paris around Paris is pretty bad)
> For a lot of destination you can take 2-3 differentes routes.
most alternative routes usually take longer and end up congested whenever the main route is having issues.
https://www.paris.fr/pages/le-bilan-des-deplacements-a-paris...
Indicate 13% of the traffic is for utilitary vehicule. This number include people taking their utilitary vehicule for personal reason. 50% is for personal vehicules.
Also, why were you driving around Paris ?
> most alternative routes usually take longer
It depends.
Also, according to one of the linked pdf, cars in Paris are barely for Paris-Paris movement, but more for Paris-suburbs, which is still the biggest weakness of the public transportation network.