Now the default purge fee for most nodes is 1sat / byte and it's quite reasonable.
OP is talking about the minimum relay fee and that's different from the purging fee.
The minimum relay fee is set by the nodes and the default value is now 1 sat/vbyte. Any transaction paying less than 1 sat/vbyte is considered non-standard and would be rejected by any node with default minimum relay fee.
The purging fee rate isn't set by the nodes directly and that's the function of their maximum mempool size.