When Do Bitcoin Node Operators Upgrade?

"Before July 2018 it generally took 1 year for 95% of node operators to update their software. But after 2018 it doubled to 2 years. And it's entirely possible that we're now in an era of it taking 3 years for 95% of node operators to update!"

https://www.nobsbitcoin.com/when-do-bitcoin-node-operators-upgrade/