That makes sense, I think that's more of a reason for not enforcing the streak so strictly. Giving levay days helps you not obsessed over it. Also, for a user who lost his streak and is devastated over it, I do think Duo support helps them restore it. I do think they realize it's just a number and there is not need to traumatized people over losing it.

On the other hand, may be it should not be things like obsession at all?

Many important things in life like fitness, diet etc are very repetitive and hence boring to some extent. There are times when you just to have to get through the grind even if you are not interested or you are aligned with it. The point being don't just depend on the initial euphoria of things to do a thing that's good. If something is good on the longer, at some point it does get a little boring, and that's ok, just keep doing it.

There are things that I stopped doing because I was bored and a few months later I had like a moment of epiphany- It wouldn't have hurt me if I had stuck to this, quitting has cost me more.

May be one should think beyond doing things for immediate emotional relief.

It much harder to stick to routine without any short term rewards. Human brain priortizes short term rewards. Logically it makes sense to me that good habits will give fruitful results over long term (like learn french everyday over two years) but in short term i need something to keep me motivated (like streak)