I never said this was the only argument people made. But it is one of the strawmen/distractions that are commonly thrown up in at least some areas.

To answer the bullet points you made:

>1. Special interest group capture has made building public transit impossibly expensive. Waymo's entire $30B valuation wouldn't even fix NYC's subway and finish the 2nd ave expansion.

Yes, a lot of public projects are allowed to be overblown in budgeting. This has many causes and they need to be addressed, but it is not a reason for halting all infrastructure improvement. It is simply a problem orthogonal to the one being discussed.
But on the subject of cost, public transit can definitely be way cheaper than car ownership for the individual. (Yes I know fares are subsidized but so are roads and other car infrastructure, so that all needs to be balanced before claiming public transit is just the upstanding taxpayer paying for the poor and filthy).

>2. American's don't like public transit because it involves being in confined space with other people, and a variety of cultural factors make that more unpleasant than it is in other countries. There is no culture of shame here so people on public transit are commonly extremely annoying and there's no law enforcement in many large cities so you just have to deal with it.

That sounds like another problem that needs to be dealt with entirely separately, but there obviously are a lot of US cities with massively used public transport without there being more crime there than elsewhere in the city/region.

>3. Most americans live in suburbia where robust public transit just isn't possible. It can be improved but mostly that just means commuter rail which still requires using a car for everything other than commuting, and usually people drive to the commuter rail station anyway.

Even if they do, that still goes a long way towards solving the traffic jam problem, because it's the physics of the car itself that creates the jam. There just can not be enough cars on the road for everyone because there simply isn't space. Those that absolutely need or want to use it should be able to, and that is made easier when more people use transit.

>4. We already have all the road infrustrure needed for transportation

See point 3, no we don't. We can not because there isn't space for all the cars at the rush hour times.

>5. Even in the best of circumstances public transit is more of a hassle than just driving directly from point a to point b

That's perfectly fine. If I can save myself the cost of a car I am happy to walk a bit. Not all will make that cost/benefit calculation and that's fine too.
But really, the exact time when it is a complete pain to drive (rush hour) is the time where good transit beats the car anytime, and also the exact time when every single transit passenger is one less car on the road, being in the way of all the other cars.
Lastly, the micro-mobility devices of recent years really do solve the problem of this for many or most.
It takes me very little time and is quite enjoyable, to rent a scooter in the morning to get to the best bus stop to get to work. When there I can walk to work or if I need to go further I rent another scooter.

All this to say, good and robust public transit is a win-win for every person in the town/city. Except perhaps the car dealership owner.

Edit: Oh, and I can't believe I forgot to mention, given this thread. The ultimate solution to the last-mile travel for longer distances is indeed self driving cars!