I am sorry for the job seekers if they get lured by some bewitching job posts. These whatsapp job groups claim to forward jobs but where is the credibility? Expired vacancies are shared on-and-on and forever. Job seekers apply and then blame they did not hear back.
Yes, there might be instances of few success stories but I don't consider it to be discussed even. Its 0.1% in 100%.
I would encourage job seekers to focus more on;
▬ Job Portals
▬ LinkedIn Jobs
▬ Networking and Industry Events
If you are a kind of person that you would forget to follow the updates and need to get feeds then put an email alert for relevant jobs. Its not only more practical but you have range of options to set your 'search engine'.
Your mobile number is your personal property. Do not give away in Public & specially for WA groups. It makes more sense to have a 'job group' on LinkedIn and let people join in. Profiles can be viewed and referral process can be much faster.
People do not stay in WA groups for a fact.