I could see this being a viable alternative, but it appears to be missing a key feature for us, analytics. As an B2B SaaS app, we have support SLAs that mandate specific response times. HelpScout makes it easy for us to report response times. We can also tag support themes to help focus product development; being able to see metrics around theme frequency is very important.
Analytics also tell us which Knowledge Base articles are most popular as well as phrases users search so we can be sure we surface the correct article.