Sure, so when Eth was supposably POW, Eth had the difficulty bomb. This made it impossible to continue the chain after a certain block height and the only way to continue the chain was to install a Vitalik released software update.

In other words, the consensus was whatever Vitalik wanted and not made by sovereign node runners in the system. Even without the difficulty bomb, the cost the run a node on Eth was prohibitively expensive so the average user was never going to be making consensus level decisions about what gets to happen to their money anyway.

In stark contrast, Bitcoin has no back door like Eth had under POW and changes are made through multi-year discussions among people who will reflect their decision in the software that they run once there seems to be pretty good agreement about a change.