I don't want to dismiss this post out of hand, but the last few instances I've spent any time browsing Indeed, it did not strike me as representative of the tech hiring market.
Where's the LinkedIn data?
Where's the LinkedIn data?
The drop could be just the result of some of those firms ceasing their activity as I definitely don't see as many CyberCoders and whatever was that bot, which automatically reposted vacancies on Linkedin (JobNetwork or something), in the recent months.