What is the point of a 20 minute interview?

Question

Career in IT

I had a strange interview the day before yesterday on Skype without video.
The team leader spoke for 10 minutes. 10 minutes spoke hr. asked a couple of general questions about the experience.
They spoke in a sort of apathetic way, as if they did not care at all about who I am and what I am.
Before that, I did a test task. They said OK. Moreover, the turnip was indeed cloned the day before yesterday and yesterday.
They promised to announce the decision on Monday.
I have some mixed feelings. As if they just give a test and just interview you for show.
I was expecting something else.
Have you ever had such strange interviews?

Answer 1

the decision has already been made

Answer 2

I went through a quadrillion of interviews in 5 years, they only started taking me this year, so don't be sad, now I have 12 competitors - everything looks like bums, I'll smash them

Answer 3

We have already found a person, but we must report to the authorities about the huge work. matter of life.

Answer 4

They simply lost hope of finding a good (knowledgeable) employee ...
Therefore, already, from fatigue, they are talking.

Answer 5

Recently, there are a lot of "login" and people in IT who overestimate their grade, so some companies practice short interviews to evaluate a specialist.
If the interview results are positive, they are invited to a full-fledged interview.