First, you need to keep in mind that the opportunity cost is associated with the profit and not the revenue. $19T in revenue doesn't mean jack if it cost you $20T to make it (aka, a profit loss).
You seem to think that the $19T/$20T figures are profits, but they're not. They're the potential revenue, yes, but the final profit (and opportunity cost) is after you take a chunk out for expenses. And if it costs you $18T to make that $19T in revenue, you're kidding yourself if you don't think that potentially doubling your profit margin is 'insignificant.' But, of course, we have no idea what the expenses would truly be like so that's all just a theoretical.
But that leads to the second point, in that business/investments seek to maximize profits. And the idea that any entity will just act like "Eh, an extra 5% revenue is insignificant." is completely wrong.