If you are suggesting that there we are going to order a pizza in Satoshis, nobody is arguing that. The normal unit of currency will always be dollars, except as you point out for large transactions like houses.
However, you will absolutely be able to swipe a POS sale application and pay with BTC. It may be as simple as large banks allow you to pay your credit card statement with BTC. However, there are already a few POS BTC applications from small companies. I don't think the Lightning Layer 2 solution is technically ready yet, but there is VERY little reason to believe it can't be worked out. And by worked out, I mean it solves the transaction cost problem one way or another.
The tax thing is a complete nonissue.
Now, probably YOU won't be buying stuff in BTC. But there are >50 million Americans, many of whom hold highly large volumes appreciated BTC. You could be right, big companies no longer care about profits. However, I think they do. Now that large institutions are involved it is only a matter of time.