> A 16-bit microcontroller (< 5 USD) would pull it off, but you'd need to custom code most of the software to power that.

So it's an engineering trade-off: You "don't need" something complex, not at all, nope (but if you use the "simpler" solution, other parts become more complex as a result).

I've noticed this multiple times before, and it annoys me: "Simpler" is not always better; in fact, it isn't even always simpler!

I don't mean to jump on you in specific, but this idea does come up again and again, often in places like Hacker News.