A lot of big companies have come and go. It's not just small ones.
Airlines, department stores, manufacturers, a lot of heavy hitters are now gone. Their assets have been bought by other companies and it continues on, like a weird reincarnation cycle or something.
This is why some investment advisors recommend investing in an index fund, rather than in individual stocks. If you own stock, the company might die off. If you own the index fund (VTSAX, for example), chances are it will still be around and will hold new company stocks. The fund refreshes itself by pruning the deadwood and adding the new companies.
There's a lot of debate about whether the big companies should have been saved from themselves in the Great Recession of 08-09. Personally, I don't think they should have gotten bailouts. It basically allowed certain problems with these companies to continue. Because they were allowed to survive their own bad decisions, we are going to have to deal with it again in the future.
On the other hand, would allowing them to die have caused another Great Depression? I guess we won't ever know for sure.
But those companies did not deserve to survive. They shot their own foot with their bad business decisions and they should have suffered the consequences for it.
Some people refer to Iceland, which did not bail out their banks and industry. The result was a rapid, hard correction to the market, followed by a remarkable recovery. But Iceland is a much smaller country. Is it an applicable example for the United States? At the very least, I think there are lessons to learn from Iceland's example.