When to use "venir siendo" instead of "ser"?

Question

I've just seen the expression "venir siendo" used this way:

la niebla, que vendría siendo el cielo…

I was asking the person who wrote that to explain (among other things) what "la niebla" was supposed to be in their story, and the reply is apparently "it would be the heaven". As a simple language learner, it would be natural for me to use "sería" in that case, and I was quite surprised to find out that a construction like "venir siendo" exists. So I'm wondering if it's just an equivalent option, or there's some reason the phrase would be preferred.

Answer 1

The phrase "vendría siendo" can be translated as "turns up to be", "ends up being" or "happens to be". For example:

• la niebla, que vendría siendo el cielo -> the fog, which happens to be the sky.

So, "venir siendo" is roughly equivalent to "ser", but adds a touch of indirection and perhaps evocation.

Answer 2

"venir siendo" is an expression with no other meaning than "es" but sounds like It has been "appearing" slowly, or that "in this case, it looks like it is the sky". It is a very complicated expression, not common at all in spoken language, but it is on written language.

There's a funny phrase very common in spanish from Spain when you say:

-¿Te interesa? (are you interested?)
-Me interesa lo que viene siendo poco.

Sounds a little "awkward", as if you were trying not to say it very rough and direct, because you could just say: Me interesa poco.
But it is like using "old" expressions, it sounds even funny. But understandable and correct. Not very common to use, though.