Online: You can perform further self-guided research to discern what these terms actually mean and whether you need those features or not. Furthermore, you can see what other people thought about those features.
In Person: You can have the salesperson explain those terms to you. Except... do you really trust someone with a direct financial interest in your purchasing a new car to help you figure out whether you need features and whether this car is the right car for you?
The primary reason to get the dealership out of the picture is, to get the salesperson out of the picture. You don't buy a toaster that way, or even a house. Why a car?
I actually like doing a lot of initial research face-to-face with a person. It's higher bandwidth, and the car is there in front of me, so I can get a sense of the intangibles and other facts that are hard to capture online.
And direct you towards something they have in inventory, not the configuration you came up with on the manufacturers website.
For how long? It's a product an older generation that, for some reason or another, appreciates receiving the sales pitch. We're all tech savvy people here; go into Best Buy and start looking at computers. 4 out of 5 times you'll receive a sales pitch with, at least, a few elements of utter bullshit.
Meanwhile, the younger generation are becoming more and more comfortable with buy things online, sight unseen. The GP said it needs to see and feel options on a vehicle. I don't. I need to know what they do, and whether they work (information I can gather from reviews). In my experience, going and playing with something for a brief period of time at a dealership or store doesn't provide enough real world information, and I'm just as likely to make the wrong choice about a feature.
Maybe not, though a lot of people do and you probably should. The ergonomics of a car are more important, and much more complex, than for many other items. Some of this is addressed by adjustable seats, but not all of it. Zappos solved this by doing lots of returns, but that's not a great solution for large items with high shipping costs.
That said, I could easily see the value in having a single specimen at the showroom to check for fit, and then having everybody special order one with their own trim level, colors, etc.
Much more so with cars -- e.g. how would I tell whether 0.5" less elbow space is still good enough, or how good is road visibility from the driver seat (IMO the single most important characteristic of a vehicle!), or whether the plastic feels cheap, or how clear/useful the HUD is, from looking at pictures?
Thinking about it, I've picked my last car based on rear seat headrests obscuring rear visibility too much for my liking in one of the last two contenders. I wouldn't have been able to notice it without actually driving the vehicle.
Sure, there are reviews & ratings, but those reviewers are not you -- if (for example) you don't care about those headrests quite as much as I do, why should you let my opinion skew yours?
I recently spent some time on many car companies' websites and navigating the options is extremely difficult. They use all their marketing jargon like sDrive vs. xDrive or 4MATIC or whatever else other nonsense. They don't explain well what any of them mean, and I was left googling the definitions of everything.
Then you get to being actually able to see the car with the various options that you're interested in. The article decries the fact that dealerships have "$100 billion of unsold dealer inventory" but that inventory has a purpose. Some people need a car right away and they aren't picky about it being the exact thing that they want. Some people want to actually see, feel and use the options they are considering.
So I'm against the government-sanctioned ban on direct sales but I think that car dealerships would serve a purpose and survive without it.