If you're selling tech: they'll often rather buy you than spend time solving the problem themselves. Most things can't be sped up by a linear factor if you apply more money/people/resources, so they'd still need some time to catch up to what you do. Granted, they'd need less time, because they could do development, marketing, infrastructure etc in parallel, but still: they'll usually prefer not wasting that time and acquihire you (and your team), to go to where you are in a very short time and have domain experts on the team immediately.

That changes if there's a lot of competition of course, they might buy your competitor and throw their weight behind them.