Apple's goal is making good products. If they wanted shitloads of cash, they could have sold out at any time in the last decade. Instead, they try to make things that people will love.

If Apple has no competitor, they'll continue to innovate, have no doubts. However, they might not innovate in all ways at once, meaning they might not focus on annihilating all their weaknesses. If they've got a competitor, suddenly there's incentive to beat their rivals in every way possible, and the resulting products are even better.