GSA SER is still used by some blackhat/parasite SEO people, mainly for churn-and-burn projects, tiered backlinks, and indexing support. But it’s nowhere near as powerful as it was years ago because Google’s spam detection is much stronger now.
Main problems today:
- low-quality links getting ignored
- footprints
- captcha/proxy costs
- frequent platform dead links
- higher risk of penalties
Most serious SEOs now combine it with better strategies like parasite SEO, expired domains, cloud properties, Web 2.0s, and AI-assisted manual links instead of relying only on automated blasts.
So yes, it still works in certain cases, but not like the old days where you could rank almost anything with pure automation.