> * Some people have mobility issues and can't bike or walk but can drive.
A simple bullet, but with many nuances buried. There is no single answer. Below are several observations. No one of these is intended to be an answer. But there are a panoply of choices a city can make that improve access and mobility for all.
Yes, and good bike/ped infra is good for them, too. Everything that makes a good bike lane (smooth pavement, wide enough for passing, minimal bumps and potholes, at grade without having to go up and down to cross streets) also makes a great place for a mobility scooters.
Not everyone uses a mobility scooter. Cities with extensive pedestrianized areas typically do not close these to deliveries, and many leave them open for pick-up/drop-off for those with mobility issues.
The items mentioned above are about stopping general car traffic either in portions of a street or on a whole street.
Not all traffic reduction necessarily means a reduction of car-navigable streets. Traffic reduction can take the form of reducing through-traffic. There are many implementation mechanisms for this. One mechanism is a modal filter, which allows through-traffic for non-motor vehicles, but prevents through-traffic for motor vehicles (side note, such filters can be constructed such that emergency vehicles can still pass through). Thus through-traffic is prevented, but door-to-door vehicle traffic is still possible.
But modal filters can make routes more circuitous. Yes. Optimizing a city does not mean optimizing just the transport infrastructure, and optimizing transport infrastructure does not mean just prioritizing a single mode above all others. That said, generally reducing traffic improves driving experience and reduces times, because there is less traffic. A more circuitous route can be made faster with sufficient traffic reduction.
But circuitous routes increase emissions. They increase emissions for those cars which make the trip, but save emissions based on all trips that are shifted to other forms of transportation. Even those marginally longer trips for the remaining cars may be emission-neutral (or at least not as bad as naively expected) based on reduced idling time and smoother travel.
Nothing above is to say cars should be banned. Just observations about design choices that are routinely made around the globe that are generally considered good urbanism and have not led to major negative outcomes. Nothing to stop you or any individual to choose a car, just design decisions that do not prioritize cars above all else.
> * Cars give you environment isolation when it's freezing, sweltering, or pouring rain.
Yes, so do all forms of public transit. Shelters are routine in good transit systems, and any form of metro or rail will typically have buildings or underground stations.
There is, of course, wait time for transit, which is all the more reason to optimize a system for frequent service with dedicated rights of way or grade-separation. Frequency is also one of the greatest drivers of ridership.
In urban areas it is common that a vehicle is not directly outside your front door or in a covered garage. Similarly, that parking at the destination may be some distance from the door of the destination. This is analogous to the walk to a transit station. Obviously this varies by person and situation.
Cars avoid the dwell time at a station, emphasizing the value of shelters and facilities at transit stations.
Certainly a car is more convenient than transit in inclement weather. This is not a reason to design transportation infrastructure optimizing solely for personal vehicles.
> * Cars make it much easier to haul stuff around.
The vast majority of day-to-day trips do not require hauling, unless that is part of your job. Certainly, if it is part of your job, you either have such a vehicle or it is provided by your employer.
Such hauling-based jobs are vastly improved by traffic reduction measures. Less traffic means better delivery times, and more importantly, more reliable time estimates for delivery. I know of no one in logistics who would decline to trade a small fee for improved times and reliability.
For personal use cases, as I mentioned hauling is rare. For the vast majority of people, the justification of hauling is better met financially by a van or truck rental as needed than by owning and maintaining a vehicle full time.
To be 100% clear, I am not saying, "you should not have a car, because vans are good at hauling." I am saying that "I occasionally need to haul things, so I need a car" is a specious argument. I am not saying you or anyone else should not have a car. I am simply pointing out that "occasional hauling" is not a good reason to own a car. If you want a car, have a car! If someone else wants a car, let them have a car! If you value the convenience of using your own vehicle for hauling at a per-use rate that is a large multiple of the rate of renting a van/truck, that is your own value judgment and you are welcome to it.
This is simply an observation that for the vast majority of people, the financial analysis suggests not a car, but a van/truck rental for hauling purposes. If you are not part of this majority, then please recognized that I am not trying to say that you are.
Hauling is a totally valid use case for vehicles and I've never seen anyone make an argument that the transportation of goods and stuff should be forbidden. Certainly I hope no one interprets my statements above as such an argument. The need to transport things, again, is not a good reason to build an entire transportation system in a city to optimize always for personal vehicles.
Again, a very common feature of reduced traffic, and even traffic-forbidden areas in cities is that they are close to most traffic, but still allow deliveries and mobility assistance vehicles.
And also, again, a reduction in traffic is a boon for those use cases.