There will be plenty of opportunities to evaluate communication during the other stages of the interview.
It's lazy on behalf on the employers.
What if you're talking about interviewing thousands of people, a number of which are passable on paper?
It's a search problem, not laziness.
When I change jobs, I can't schedule bazillions of 1h phone screening on top on my work time at my current company, only for the interviewer to not show up or realize they don't really have a position available. I'd rather have a one hour test from home, whenever I want.
We provide engineers with free, live (and anonymous) interview practice. If you do well, you get fast-tracked at top companies.
I also agree with the lack of interaction being a problem. I've always thought about this in the context of value symmetry. If you are expecting people to put time into a coding assignment, you have to give them something useful back... especially in a market where good engineers are the ones who are scarce, not jobs.
As an engineer, you work with other humans first and machines second. Platforms like HackerRank seem to miss that, while better ones like interviewing.io put it front and center.