The unintended consequence of a blockchain becoming successful is that it being increasingly centralized.
The 60% probably represents the mining nodes.
When we are looking at the nodes which actually submit transactions the number of nodes go to a much smaller number.
The majority of the DeFi and a lot of other Dapps are going through Metamask and Infura nodes.
Counting the nodes of wallet providers and centralized exchanges the number may become 1–3 dozens of nodes…