Or the technical challenge being ridiculous like a lot of them are. If you have that many people failing it, that tells me some or all of these things are true:
Management, or whoever they hire for handling candidates, is not screening them well
The challenge is needlessly complex
The challenge requirements are not clear
The company expects absolute prod-ready perfection but told the candidates “don’t spend more than 2-3 hours on this,” despite it taking one of their own engineers 6-8 hours
The salary is way too low and they’re not getting candidates that fit their demands (e.g. wanting “senior” while offering “junior” salaries)
Seriously, some tech companies think they shit gold and give ridiculous challenges that reflect that delusion.
Source: been in tech since 2005 and in a terminal since I was 12.