Software, as an industry, generally profits the most when it can identify an existing need that is currently solved without computers, and then make it 10x+ more efficient by applying computers. - HN

In this situation, the software doesn’t need to be bug-free, it doesn’t need to do everything, it just needs to work better than a human can. The requirements are usually ambiguous: you’re sacrificing some portion of the capability of a human in exchange for making the important part orders of magnitude cheaper, and it’s crucial to find out what the important part is and what you can sacrifice. And time-to-market is critical: you might get a million-times speedup over a human doing the job, but the next company that comes along will be lucky to get 50% on you, so they face much more of an adoption battle.

Under these conditions, TDD just slows you down. You don’t even know what the requirements are, and a large portion of why you’re building the product is to find out what they are. Slow down the initial MVP by a factor of 2 and somebody will beat you to it.