How ofted do you use Future Perfect nowadays

How often do you use Future Perfect in the US and UK? How does it sound to you?

I will have visited Asia by the time I am 30 years old.

The mankind will have colonized Mars by 2030.

For example:

a) We use it (regularly, seldom).

b) We don't use it but it sounds nice.

c) We don't use it and it sounds awkward.

Answer

We use it when we need it, and don't really notice.

But it is not clearly needed in either of your examples. Simple predictions are ordinarily expressed with a will + infinitive future:

I will visit Asia by the time I am 30.
Mankind will colonize Mars by 2030. (Incidentally: no article with mankind)

But if your context establishes that such an event acts as 'background' for some other predicted event, a future perfect construction is called for. For instance:

I will have visited Asia and be ready to start writing my book about it by the time I am 30.

The only hope for the survival of the species is that mankind will have colonized Mars by the time our oil reserves run out in 2030.

You only use the future perfect if your story includes some future event—not just a date—to which the fp event is necessarily anterior.