Well almost 24 hours ago as I am writing this, the 19th millionth bitcoin has been mined. The 18th millionth bitcoin was mined in October of 2019 so I think the 20 millionth bitcoin will be mined probably in 2024-2026 or maybe 2030 but time will tell. Maybe all the somewhere in the 2030s, the 21 millionth bitcoin would be mined and that is my opinion of predicting of when will all the bitcoins be mined.