For example, apps like uber or ordering apps, saturated market, but what if you could deliver the service at a 30-40% lower cost (all other things being equal). Is this model a good idea or is it a race to the bottom?
It is definitely a race to the bottom, you could look up a case study on a company called tiny owl in India, they raised millions of dollars to compete in this space and their lesser funded competitor at the time, Swiggy.
Now Indias 2nd largest food delivery platform, this case study provides multiple insights,
1. Cheaper doesn't mean better even though it's an identical service
2. Even within zomato and swiggy there are extremely loyal users to each app not because of price but because of their ease of ordering, to each their own
3. There is no way you can compete with them on price, even after being funded and having scale on their side they still aren't profitable, zomato is valued at $5.4 billion
If you do have any ideas for a business, happy to discuss