At that time you even had bitcoin faucets that gave you 0.5-1-5 btc to play around. Or you could just run a miner on your gpu and get 50btc if you ran it for a few days or so - a ton of people probably have those on some partition on an old laptop or sth.

Yes, but we know where those coins are now: in circulation. And we have a good grasp how many that is and how many could possibly on on those shelved laptops. It is literally how every coin in circulation was minted as there is no central party, only your peer devices.