Do not mind my little knowledge about this, but I think people can run full node even without Bitcoin Core? There are other full node wallets.
It's true there are other full node software beside Bitcoin Core, but Bitcoin Core remain most popular one. It's also worth to mention Bitcoin Core still offer best performance,
https://blog.lopp.net/2023-bitcoin-node-performance-tests/.
Is that warning not pertaining to Bitcoin Core but to bitcoin generally?
IMO the warning only applies to Bitcoin Core software.
All other nodes and miners still kind of depending on Bitcoin Core to run full node?
No, you can choose to other full node software or even write new one for your needs. But i expect most or all alternative use Bitcoin Core as reference.