You're missing price. Compare your trip to Public transit costs, and include infrastructure costs. You had to pay for your vehicle, your car insurance (which in the US there are irresponsibly low legal minimums), registration, gas, and also taxes for the infrastructure, to get yourself somewhere which takes up more room than needed (usually several times more room than a combination lf walking and public transit). Public transit only requires fare pricing, along with infrastructure, which is significantly cheaper per person due to more efficient use of space.

Compare many European metro cities to the US, and you'll notice their public transit is more convenient (in the characteristics you have pointed out) because we decided to shut ourselves in the foot as a country and forced everyone to have to get a car payment, while making public transit bad.

Of course, public transit isn't convenient for every area, such as rural towns in which personal vehicles are a better solution, but we have many cities where there should be significantly better public transit.

This only works if you live in areas with no traffic. I have had multiple commutes in different cities, and would take a train whenever possible because of how unpleasant the drive is during rush hour (not to mention driving took longer, in one case 2.5x as long!). I don’t even live in a city, I’m just forced to commute because that’s where the work is. I love cars and have been an enthusiast all my life, but there are many reasons why public transportation is so popular around the world. The US might be somewhat unique in the challenges it faces with public transit, but it is still a better, cleaner, cheaper, and more efficient solution for most of the miles Americans are driving in cities or other congested areas.

shortest possible route

No. That would be a straight line like a train.

no detours, stops

Lmao. Whatever. Don't stop, genius.

the shortest possible time

That would be high speed rail.