Right, we only estimates and it's impossible to know the truth.

Buuut a huge database with notes and information per individual UTXO that is in debate could be a first step from where estimates could start to compile for themselves

Latest estimate that I remember was that 4 million bitcoin are lost forever. It is impossible to know the exact amount.

quark

bitcoin

- It's common knowledge that a lot of keys are lost forever from people who used Bitcoin in the early days without knowing at the time
- This could be interesting for estimating how much of the 21m is still in supply
- I know it's hard because there is no confirmation if what people claim is actually true
- It has to disregard "boating accidents"
- Imo it will inevitably happen that someone makes a website investigating this in depth