Those buildings and equipment and patents may have value, but less than the bonds, loans, and other liabilities IBM also has. Not only could IBM be worth $0, it could be worth less than that.
Things are worth whatever people are willing to pay. Bitcoin may be the original sin of crypto bros, but it still appears to be worth money, because it's impossible to make one for free, or obtain one for free. And it has utility. You can buy drugs or avoid the banking system using it.
Silicon Valley Bank had buildings. It was literally worthless at the end. A company is just as fictitious as a bitcoin, only existing because people all agree that "company" is a thing.
But IBM is a public company. These numbers are known. Its estimated liquidation value right now (selling off all the assets) is around $22 billion. That's pretty far from its market cap of just over $130 billion, but it's not nothing.
SVB became worthless by virtue of real changes in the real economy. Of course it can happen that a company goes bankrupt, and then its fundamental value is zero or negative. But the point is that there is a fundamental value that is realised over time. The market value is a good estimate of that fundamental value according to the EMH, but if you have a better analysis and better estimate of the fundamental value you can trade and then realise that difference over time if you were right.
Things are worth whatever people are willing to pay. Bitcoin may be the original sin of crypto bros, but it still appears to be worth money, because it's impossible to make one for free, or obtain one for free. And it has utility. You can buy drugs or avoid the banking system using it.
Silicon Valley Bank had buildings. It was literally worthless at the end. A company is just as fictitious as a bitcoin, only existing because people all agree that "company" is a thing.
(EDIT: I changed my example to SVB from Enron)