Google won’t be unseated by Bing. It will be unseated by ChatGPT, Perplexity, etc.
Android/iOS won’t be unseated by another mobile OS. They will be unseated by a Voice/VR OS that uses AI to give outcomes with minimal user input.
This leads to the question: How does one unseat the “default”?
As a startup, you cannot just be incrementally better. You cannot be 10% faster or 20% cheaper or 25% more efficient.
The “default” can quickly improve in those areas to recapture marketshare.
What you need to do is change users’ expectations of value from the platform.
And that “value expectation” comes from deep insights into how the customer’s problem statement has evolved.