[Gigachad]

What is worse than being interrupted is spending days in deep focus only to find out at the end that you made a foundational mistake that invalidates the rest of your work. Through no fault of your own you could have the wrong understanding of what the user wants or how it fits in with other parts of the system. Being able to quickly sync up with the end user for a change or validate your ideas with another developer is so valuable.

If you need to wait a day to get a response from anyone, you either have to drop the work and do something else while waiting (breaking your deep focus). Or assume you are right while waiting and risk throwing out a days work if you are wrong.