[Festro]

This activity would trigger Google's Spambrain algorithm and ensure the backlinks were fully ignored.

Depending on the volume (100k is a lot) a human check may be made and result in a manual action against the site which would lower discoverability.

Discoverability correlates with link velocity, if velocity is uneven it is suspicious and punished.

It would help crawling and indexing technically but that's something you can do for free via Google Search Console with sitemap submission and manual index requests.

Automated backlink creation is and always will be a 100% bad idea in the short and long term. It is a waste of money and effort and only every something scammers and bad product managers endorse for their own benefit. Any positive effect always turns out to be misattributed.