Interesting question: would it be worth a premium to buy control of a public company? Are there examples?

Assuming we are talking about one-share-one-vote company, there are complications...as you cross various thresholds of ownership you may be required by the local regulators (depending where the company is based) to stop buying before getting approvals, or make a bid for the entire portion you don't own. Barring those hurdles, though, you could just keep buying till you have control and then vote yourself a new board if you liked. Perhaps useful for setting the capital allocation strategy to something that suits you.

For companies with super-voting shares, I think a fair generalization is that the voting shares are really worth a premium, but only to a very specific set of individuals. If you're not one of those few, the votes are worth nothing to you, except in one way: those few individuals will normally be the ones bidding the extra that makes the voting shares have a higher price, so there may be a price premium you can realize when you sell.

Alphabet is really a strange exception in that regard. It makes no economic sense that the voting shares trade more cheaply (though of course supply and demand can trump economic sense for quite a while). This oddity is relatively recent, too: the voting shares traded as expected at a small premium to the non-voting shares until late 2019.

Jim