So I recently found out that during satoshi era like pre ASIC
All nodes were miners.
https://bitcointalk.org/index.php?topic=48.msg310#msg310As can be seen by the post of Theymos, he was rewarded with a fee as well as the Block reward as a
Node Further reading made me realise that miners and nodes were used interchangeably and Not separated like we have today.
And the model that one machine does everything stopped making sense.
The world changed and Bitcoin adapted, which shows that it's inevitable for Bitcoin to remain same as the world is changing.
I would like to believe that am right by saying that all miners run a node while it is not every node that is a miner.
I think also why this idea came to be is due to the original fact that initial Bitcoin software performed both the miner and node functions, hence why it is that you said every node was a miner as the subject of discussion.
The world is changing and adapting fast and that is how Bitcoin is built to function, by evolution and by innovation of its working systems.