There's no compounding interest here. You have to look up what the share price was every month for 28 years to find out how many shares you would buy (after trade fees) and then also keep track of share splits and dividend payments. Finally you add the total dividend with share number multiplied with current share price. I promise you that Perplexity AI didn't do a single step of this. Instead it put down something that sounds likely.

Finally you have to throw all of this away since the premise is completely flawed. It's not Jeff specifically but the fact that capital is taxed less than labour people are protesting.