I'm not even sure where to begin on your confusion here.

1. Firstly, efficiency concerns the ability to more with less. Zero is less, and there's no reason why zero is substantively different than paying $0.01 per car - it's on a continuity that affords the same analysis. So saying you reply "has to do with free" speaks absolutely nothing about my initial arguments focused on efficiency.

2. Money is a veil. Like the discredited mercantilist beliefs century ago, you're confusing output with money. What matters for prosperity is the quantity of goods and services being produced in an economy. You may not realize it, but your argument is essentially granting authority of money over output in estimating prosperity. Output - the actual goods and services produced in an economy - is what matters (and the consumption we enjoy therefrom), not whatever dollar value we assign to them. This by the way is an extremely common confusion among non-economists, so don't feel bad about misunderstanding it.

3. Since you seem so fixated on this concept of "free" sidestepping my arguments, let me take your analogy and present another similar one. Imagine that it's the year 1910 and the price for buggy whips is $25, with a thriving industry producing them. It's already clear that I'm claiming efficiency improvements resulting in a price reduction is a good thing. Now let's introduce your concern: buggy whips are free! "Therefore an existing market was destroyed." Yes, this market would be destroyed. And in fact it was - buggy whips were free in the sense that cars displacing buggies simply did not require them. There is no economic difference here. Yet no one with the knowledge of hindsight today wouldn't even think about arguing that the production of value which is essentially "free" in that case is something "bad", and it's not clear whatsoever that there is some net decline in jobs (in fact all evidence points to this being precisely the opposite - touched upon by your point "There might be more jobs in the new industry").

4. Speaking of net decline in jobs, I'm disputing this being necessarily a problem at all. To say otherwise is to ignore trade-offs and categorically value one thing over another as a society. Jobs are another thing people routinely confuse with prosperity, and they also tend to believe that they are somehow assets instead of transactions. It's like saying "buying a car" is an asset, instead of the car itself. With labor, the software we produce is the asset, not our job that allows such production to take place via a quid-pro-quo. If I could purchase everything I wanted to live by for $1, I'd only work one hour the entire year doing some freelance, and not have a job. Is "not having a job" bad in that sense? Not really - but the point is it depends on the amount of consumption I'm able to enjoy, and the job is just a transaction that effectively grants me consumption purchasing power. It's the seen vs. the unseen that makes thinking about these issues (and really most things in economics) very difficult.

5. You made an important point about willingness to pay, but drew the wrong lesson from it. You seem to think that having a high willingness to pay and a low price ($0 in your example) is a bad thing, but this is precisely the opposite of the truth. In fact this is the very definition of "Consumer Surplus", the net increase of which is a good thing. See my point (1) concerning actual output/consumption being what matters.

6. Really this all boils down to your closing argument, "Therefore an existing market was destroyed", and focusing on some costs and benefits while completely ignoring others. Whether or not destruction of any particular industry is good or bad is not relevant unless you fully account for all costs/benefits. Actual accounting for this empirically is difficult, but axiomatic economics shows that advances in efficiency and producing more with less is precisely the way growth occurs - a net benefit.

To fully explore all the issues here would require much longer. Hence is the simple fact that making nonsense claims takes one paragraph and carefully explaining the often non-intuitive economists implicit in such claims takes 10x as long. Sounds like some debate asymmetry if there ever was any.