I think these White Board Tests are not important but similar should be there.
They do not show that you know how to solve that specific problem but
What we miss in a company interview is that it is not a one-man job; it's a team game and it has to be played as a team.
Consider Football, if Messi could have scored all the goals alone, still he will not be able to win the game as Team is all the gears needed to function as a single unit.
I talked to many developers, and I always come across this question of the importance of this kind of whiteboard interview process.
Whiteboard Interviews or similar process is important to be not thrown away but not that important to reject people straight away.
The above statement is ambiguous in itself but you need to give time to analyze a candidate. And once you have analyzed enough, share your analysis and opinion honestly. Like I value Data Structures more, could you implement with certain Data Structures or what if this problem of 100 entries scales 1000 times