Buying shares means you own some of that; that is the value.
These companies likely pay their employees, and as a shareholder you get to partake and harvest value, without having to work for it.
If the company earns more than last year, the stock should be worth more. But of course, valuation clouds the picture, where dividends are usually simpler to model.
It’s no more “a piece of paper”, than a deed over a piece of land is. Would you also consider that “a collectible”?
You’re entitled to have your opinion, but I disagree with you on this.
Amazon currently has close to 11 billion shares of stock (https://www.macrotrends.net/stocks/charts/AMZN/amazon/shares...). Do you seriously believe that 1/11,000,000,000th control over Amazon in terms of voting rights is worth $240? A single vote is indistinguishable from meaningless.