Except that the introduction of multiple decks for a single table made card counting all but useless
I call shenanigans
Not necessarily true. People still succeed at card counting with 6 deck shoes. The main problem is that you need a lot of capital for the odds to eventually even out in your favor. Even in the bast case scenario, you still only have a 1% advantage. There are counting groups that will pool tons of money and then split the total winnings as to maintain a higher average winnings.
It still works, just not as well. There are plenty of youtube videos teaching how to count cards even with multiple decks.
Sure, but automatic shufflers are getting more and more common. Not to mention, you have to have a fairly large starting pot to have a hope of making a decent profit. Then even if you do everything right, you still have a relatively high chance of going in the red.