Average skill level of average front-end devs in India

Our company has been trying to hire a front-end dev since some time now. I've interviewed candidates with 6-10 years of experience, working in TCS/Accenture/Cap Gemini etc.

When I ask them how they would rate themselves on a 0-10 scale in JS, they all say 8-9. Just to make sure, I ask them to screenshare and do this task.

This is from Advent Of Code Day 1 BTW.

3   4
4   3
2   5
1   3
3   9
3   3

Pair lowest number in column 1 with lowest in column 2, and then the second lowest from col 1 and col 2, and so on.

None of the candidates even reached half-way. All of them struggled to even declare a variable with the above as a string, i.e, using backticks. And they all say that they use React day in and day out.

I wonder how these people are handling their tasks in their current roles, if they can't handle something so simple. And communication skills are terrible too, but was willing to overlook that to an extent.

Is the average front-end dev here so bad? What has been your experience?

Edit: I'm not saying this is all they would need to solve to get selected. This was just to test their basic problem solving skills.