I can’t say the same about Stack Overflow, but the Hashnode community is definitely more friendly.
SO members sacrifice friendliness for the pretense of professionalism: many of them think if they want to look professional they have to stay dry and objective (being objective, however, is written in the SO policy).
On the other hand, Hashnode is “the Quora of developers”, and as such, allows (encourages) members to be subjective.
And people who are allowed to be subjective are usually friendlier.