It's important to keep in mind the big advantage of tools like HackerRank: They're scalable for the employer, allowing the employer to take a chance on more candidates.
Without something like HackerRank, recruiters will tend towards lesser heuristics, such as top schools or top firms on candidates' CVs. While HackerRank has its issues, it's certainly a vastly superior heuristic than the alternative for those many of us that don't have that kind of CVs.
It's also relatively scalable for the applicant, because it is asynchronous, and can be taken whenever convenient. For many people in jobs, taking a phone interview during business hours isn't easy.