Are Casino Auditors like eCOGRA really independent?

Hi everyone, I'm new here and I have a question about casino auditors. I see many casinos say they are audited by eCOGRA or iTech Labs and that their RTP is 96% etc. Does anyone know how this actually works? Do the auditors check every game, or just the overall system? And can we as players see the audit reports somewhere? I want to make sure I'm playing at a fair casino. Would love to hear your experience with audited casinos vs non-audited ones. Thanks!