I had the same thought recently and what I can gather and understand is that LBRY was pre-mined. So LBRY Inc and odysee hold the most when it comes to LBC and perhaps this LBC stash they hold onto is being used to allow creators to publish videos for free on odysee and LBRY.
They are also likely mining LBC as well.
However all I said above is not fact and may not be correct.