Is it really necessary to physically visit a given location in order to "truly get the place"?

Yes, I think it is true. What is lacking is a feeling for an atmosphere of a place that is often acquired subconsciously.

You seemed to have done a lot of background research for many places, which is a good idea to do.

Many peaple do to much and therefore get only little bit of everything.

This may be useful as a general orientation, where afterwords you say this one place interest me the most, so on the next trip spend many weeks to get to know it well.

If you are not a gregarious person, the are a lot of regions were the peaple there are less gregarious themselfs and won't impose themselfs that much. But you can still wander around and try out the local foods and collect impressions of a place that is different than yours.

With a proper preparation (as you are doing) and a careful selection of what suits you best, you might find it an interesting and worthwhile experience.

Such impressions (of an individual) cannot be caught in a photo or video.

It sounds more like a rant than an actual question but I understand the sentiment of the expression.

You can of course see a place from photos and videos but that is just a small part a place. It's like judging a person from their photo. You wouldn't expect a person that sees a photo of your or even 100 to get you, just as one cannot get a place by looking at photos from there. Sure, after seeing your photo, people might be able to identify you. It will be the same for any place.

To understand a place you have to be there, not because you must see it with your own eyes, but because you can experience it. It is the culmination of all that you see, hear, smell, feel and the interaction you have with the place that makes you get the place.

Equally important is that it takes time to get a place. There are many people who travel that go through places and don't get those places. The experience you have in just one moment is not representative. In order to get a place, you have to see it change, see it's people or animals or vegetation and how they live there. Sometimes its takes a while. I don't even count a country as visited if I don't spend at least one night there and even so it takes much to truly understand a place.

Don't forget that places have scale. If you land in China and spend an entire month in Beijing. Maybe you will get Beijing but you certainly will not get China. On the opposite scale, if you saw video and entire documentaries on the Carnaval in Rio, I am certain you will will not get it either, despite it being confined to some kilometers within a city. The total experience of seeing the spectacle, hearing the sound, being surrounded by the crowd and having waited in line 5 hours ahead of opening to get a good place while waiting for an even that runs all night can only be fully understood by being there to get it.

The experience of being at a place, seeing directly with my own eyes, is totally different, for me, from photographs etc.

I don't use a camera much, because I often go to places for which there are already plenty of expert photos. I buy few souvenirs. I don't go to pick up boys, and am careful about letting strangers get close enough to steal from me. I don't go to fill some hole in my everyday life, because I am happy at home when not traveling. I simply go to experience the place.

The only way you can know whether you need to visit a place to get it the way you would if you were there is to travel, at least once, to a place that is familiar through VR. If the actual experience adds nothing for you, that is enough travel. If you find being there adds to your experience of that place, go on traveling to other places.

If you don't make the experiment, you can't know what, if anything, you are missing.

1. Having been in thirty countries and taken photos in most, I'm thoroughly convinced that there is a huge difference between seeing a hundred photos of specific parts of an area at specific moments and seeing all of it over a length of time. Even a video can't compare with one's own field of vision.
2. The photographs won't show you what the traveler didn't photograph.  They will show you all sorts of beautiful things.  But if you go there, and walk down the street yourself, you'll also see the trash and garbage people have thrown to the ground, the pitiful people (or pretending to be pitiful) with their hands out, the abandoned buildings, the things that would have put the traveler in jail if he dared to attempt to photograph them, etc.
3. No written description can compare with the actual smells, tastes, textures, and sounds.
4. No written description of cultural attitudes can compare with experiencing it in the expressions on their faces and the tone of their voices.

Now, if you want reasons to stay home: (1) less likely to meet pickpockets; (2) less likely to be arrested for things that you take for granted in your own country; (3) less likely to get ripped off due to the difficulty of currency conversion in your head.