I'm involved in Bitcoin since 2012 and until 2021 I did not even hear about "taproot".
That's because you live under a rock and think you are "involved" in bitcoin. Good thing the internet is written in ink and is timestamped. There are 3 BIPs involved in the upcoming soft fork: BIP-340 (Schnorr signatures) discussion started on Fri Jul 6 18:08:34 UTC 2018 Link to first appearance on mailing list: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-July/016203.html