They do not actually.
* https://archive.ph/VCUp4 / https://www.ft.com/content/7bd1b20a-879b-11e5-90de-f44762bf9...
* https://www.pqmagazine.com/the-myth-of-shareholder-ownership...
* https://www.forbes.com/sites/petergeorgescu/2021/07/21/the-s...
* https://edwardslaw.ca/blog/shareholders-agreements-in-canada...
* https://www.ippr.org/articles/who-owns-a-company
* https://www.cambridge.org/core/journals/journal-of-instituti...
They have certain claims, but so do customers, suppliers, employees, governments (taxes), bond holders, etc. The claims of shareholders come last, which is why owning stock gets you higher returns (than, e.g., bonds from the company): you're at highest risk of losing money from being last on claims, so you should be rewarded for that higher risk.