This of course assumed that the expected earnings of the startup as an independent company run by you and your team are the same as the expected earnings of the startup assimilated into the acquirer's organisation (which might have access to new markets, new products to sell to your markets, better economies of scale. Or indeed might have a wildly inflated expectation of how much better they can monetise your service which they end up "sunsetting" four years later)
Sometimes you can have a startup you're [i]not[/i] obviously poised to make significantly money with which poses a threat to a major player's significant revenue stream, or has IP or eyeballs they value. This seems to be the case for a surprisingly high proportion of tech acquisitions.