I don't think anyone opposes that, but I don't think that's your "core claim". Your core claim is that this is a huge problem, one that makes OpenTelemetry "a technological dead-end", and that "the whole ball game is about capturing and constraining the cardinality of that metadata".

That is what it would be nice to have you justify some more. After all, the same could be said of logs, or internal traffic when using microservices/DBMS (request cardinality/traffic will be multiplied).