https://wccftech.com/ibm-unveils-the-worlds-first-2nm-technology-with-nanosheets-but-dont-let-that-2nm-tag-fool-you/

IBM, today, announced their "2nm" process technology which they are calling the world's first 2nm process. Process nomenclature is quickly becoming about as standardized as the various fashion styles out there. Almost every manufacturer has its own definition of a node, with some being more lenient than others. IBM appears to have been the first to achieve a sustainable process improvement using nanosheet technology - which is far more exciting than the 2nm claim.

Typically, process shrinks offered 50% improvement for the same die area so when companies started employing exotic techniques like FinFET and got the same improvement without actually decreasing the die size - they started drifting away from the "true" value of the node size. To be clear, not a single manufacturer right now has an honest node nomenclature, but if we were to rank them in terms of strictness, Intel's naming is about twice as strict as TSMC and so on.