For foreign companies to stop selling goods, consumer or commercial, (as well as to stop buying Russian products) is an excellent way to make Russian citizens realize that a war is going on.
There is no independent media in Russia whatsoever. Over half the population gets news from state-censored television, which broadcasts propaganda not news. I was born and raised in Ukraine and got my bachelor of science degree in Russia; therefore, I have friends and relatives in both countries. As a child I lived in the USSR, so I'm very familiar with how total propaganda works. Smarter people saw the inconsistencies in the state propaganda, but too many people just believed whatever they were told.
This tactic has been used many times in the past. In addition to the Soviet Union, Nazi Germany also sought to justify their wars in the eyes of its population. It's never "let's occupy Czechoslovakia and Poland", it's "let's protect our German brothers living there." It's never "let's occupy Eastern Europe", it's "let's help workers free themselves from capitalists." Or, in the near future, it may be "let's help Taiwanese citizens in their unspoken desire to unify with China." If you completely control the media you control the perspective, no matter how untrue it is.
Many Russians don't believe there is a war waged by Russia against Ukraine. They were told untrue propaganda of civil unrest in Ukraine, e.g. that Russia has nothing to do with fomenting civil unrest, and that Ukrainian Nazis are committing genocide of ethnic Russians, and that Russia has no alternative to protect its brethren other than a limited friendly peacekeeping action. All of it is completely false, but many Russian citizens have no access to fact-based news media, thus no way to determine whether these narratives are false and biased. So, they believe it.
For example, see this BBC article (4 March 2022), Ukraine war: 'My city's being shelled, but mum won’t believe me'
It's common for Ukrainians to have family across the border in Russia.
But for some, like Oleksandra, their Russian relatives have a
contrasting understanding of the conflict. She believes it's down to
the stories they are told by the tightly-controlled Russian media.
Oleksandra says her mother just repeats the narratives of what she
hears on Russian state TV channels.
"It really scared me when my mum exactly quoted Russian TV. They are
just brainwashing people. And people trust them," says Oleksandra. "My
parents understand that some military action is happening here. But
they say: 'Russians came to liberate you. They won't ruin anything,
they won't touch you. They're only targeting military bases'."
On Russian state TV channels on the same day, there was no mention of
the missiles striking Kharkiv's residential districts...
There are many other accounts of similar stories in the BBC article.
One way to get through propaganda is to impact the supermarket shelves. No matter what the TV says, if most imported goods have disappeared from the supermarkets, you know that something's amiss. If, furthermore, you cannot buy domestic because the business went belly up, you pay even more attention. The latter is the reason why many American businesses halted imports from Russia.
The few who have access to information are already leaving Russia. Most of Russia's oligarchs fled Russia within days of the invasion, but not after losing half of their investments. Economic pressure is effective; halting business in both directions makes people reconsider their options. Per comment, here's the source about oligarchs fleeing Russia; these are tracks of oligarch's planes flight paths, from townandcountrymag.com:
ADDED: it looks like the sanctions against average people started to work a little. Here's an interview with Baronova, a former head of a Russian state controlled news organization who just quit over the war. This is what she says, among other things:
“People were in favor on [the] first day of invasion. Now they are
less convinced and much more skeptical because they understand now
that they are going to lose their jobs, they are going to lose their
cars, their iPhones, their everything,” she said. “So, let’s see what
that are going to say in a month … The whole world is in a bad