I'm not sure I even get the question.
And from most the answers so far, I don't see the programming part being described as exhausting.
My point is: being a programmer/developer/software-engineer/no-matter-the-title-you-write-code is sometimes exhausting, but the worst and exhausting parts usually come from the interactions with other specialists (business, product managers, ....) because of different views of the challenges, priorities and even sometimes goals.
Programming itself is often frustrating, but also often very rewarding (all the times you manage to elegantly solve some challenge, find a clever and efficient way to do something, or even when you have the opportunity to remove lot of old code you just refactored)
I'm (too) often exhausted after my days, but most of the times it's not caused by the programming part directly, but by having to use programming to solve non-programming divergences between parts of the organization (no matter a 15 people startup or a 3000 employee company, I had that feeling in both situations)