Siri runs on Wolfram Alpha. Third-party would be fine, its still a task that shouldn't be underestimated. This is the reason why Google produces so little profits, yet is overvalued so highly. They own ecosystems all over the world, all over the industry. If suddenly Google shutdown everything, 70% of the internet would disappear and 80% of phones would become paper-weights. Thanks, I bleach myself and shower in parfum for you honey.