I've read the post from TOR https://blog.torproject.org/blog/some-statistics-about-onions
But they don't really answer my question, they mention that there are 30K onions that "anounce" their existance every day, but in their intro they mention
Approximately how many hidden services are there?
But they don't answer it, so I'm curious if there's some kind of way we can estimate how many onions there are.
There are metrics available for this through Tor Metrics.
See: Tor Metrics — Unique .onion addresses
The following graph shows the number of unique .onion addresses in the network per day. These numbers are extrapolated from aggregated statistics on unique .onion addresses reported by single relays acting as hidden-service directories, if at least 1% of relays reported these statistics. For more details on the extrapolation algorithm, see this blog post and this technical report.
