It depends on the objective of the coding test.

If you are expecting a candidate to have a certain skill-set, having a simple timed coding test as the first round is the easiest way to filter out a lot of unqualified candidates. Stripe does this quite well for example.

When I hire for my company, I do a live coding round with the candidate after an initial phone screen. Since I get far fewer applicants, this works out for me. The objective with the coding round is to understand more than their ability to write code in a particular language. It's a good way to learn how they communicate, how they approach a new problem, how they seek help, etc