Because Hadoop has not been killed off. In fact it is far bigger than it has ever been and growing each year. It's just that it is all transitioning to the cloud with parts like HDFS being replaced with more scalable solutions like S3/EMRFS.
But you can't say it's been killed off when on AWS you have managed Hadoop (EMR), managed Hadoop pipelines (DataPipeline) managed Spark (Glue ETL), managed Hive Metastore (Glue Catalog) etc. And similar on Azure or GCP.