Are apps like zip recruiter a dead end?

I’ve been looking through this app for years while working other jobs, and while I can find a job, they almost always seem sketchy to the point that I never find companies offering what they describe in their descriptions. What is a good way to find legitimate places of employment or even finding job fairs in your area?

usa jobs
usa jobs resume
usa hotel jobs
usajobs
usa jobs federal government
usa job in ksa
usa jobs
usa jobs login
usa jobs gov
usajobs.gov
www.usajobs.gov
usajobs.com
usajobs
usajobs.gov official